iOS复习OC语言 NSString与NSArray 使用
2016-06-03 13:11
323 查看
@implementation ViewController
- (void)viewDidLoad {
[super
viewDidLoad];
// [self demo1]; //字符串的拼接、比较、搜索、大小写互换，判断开头与结尾、抽取、互换、剔除
// [self demo2]; //动态字符串的增、删、查找、替换、判断
// [self demo3]; //深浅copy
// [self demo4];//遍历字符串、数组中内容查找
// [self demo5]; //完整路径，省略路径，扩展名
// [self demo6];//数组使用
[self
demo7];//数组排序
}
#pragma mark -字符串的拼接、比较、搜索、大小写互换，判断开头与结尾、抽取、互换、剔除首尾
-(void)demo1{
//赋值
NSString *string =
@"Hello work!";
NSString *string1 =
@"Hello work!";
NSString *string2 =
@"Hello jianguo!";
NSLog(@"string1 = %@ ;string2 = %@",string1,string2);
//拼接
NSString *string3 = [NSString
stringWithFormat:@"%@%@",string1,string2];
NSLog(@"string3 = %@",string3);
//比较
if ([string1
isEqualToString:string2])
//区分大小写的
{
NSLog(@"YES");
}else{
NSLog(@"NO");
}
//compare
BOOL result = ([string1
compare:string2] ==
NSOrderedSame); //NSOrderedSame判断两者内容是否相同
result = [string1 compare:string] ==
NSOrderedSame;
NSLog(@"result = %d",result);
result = [string1 compare:string2] ==
NSOrderedAscending;
//按字母比较，string2大于string1为真
NSLog(@"result = %d",result);
result = [string1 compare:string2] ==
NSOrderedDescending;
//按字母比较，string2小于string1为真
NSLog(@"result = %d",result);
NSString *string4 =
@"hello work!";
result = [string1 caseInsensitiveCompare:string4] ==
NSOrderedSame; //不考虑大小写比较
NSLog(@"result = %d",result);
result = [string1 compare:string2
options:NSCaseInsensitiveSearch |NSNumericSearch]
== NSOrderedSame;
//NSCaseInsensitiveSearch 不区分大小写;NSNumericSearch比较字符串的个数，不比较内容;NSLiteralSearch
区分大小写
NSLog(@"NSCaseInsensitiveSearch result = %d",result);
//大小写转换
NSLog(@"%@:%@",string1,[string1
uppercaseString]);
//大写
NSLog(@"%@:%@",string1,[string1
lowercaseString]);//小写
NSLog(@"%@:%@",string4,[string4
capitalizedString]);//单词首字母大写
//在字符串中搜索字串
NSRange rang = [string3
rangeOfString:string1];
NSLog(@"string3 = %@,string1 = %@",string3,string1);
NSLog(@"location = %ld,length = %ld",rang.location,rang.length);
//子串string1在string3中的位置和长度
//hasPrefix 判断开头
result = [string3 hasPrefix:string1];//判断string3是否以string1开头
result = [string3 hasPrefix:string2];
NSLog(@"hasPrefix result = %d",result);
//hasSuffix 判断结尾
result = [string3 hasSuffix:string2];
NSLog(@"hasSuffix result = %d",result);
//抽取字符串
NSString *str1 = [string3
substringFromIndex:3];//从索引位置截取到最后
NSLog(@"str1 = %@",str1);
NSString *str2 = [string3
substringToIndex:8];
//从开始截取到索引位置
NSLog(@"str2 = %@",str2);
NSString *str3 = [string3
substringWithRange:NSMakeRange(6,
6)];
NSLog(@"str3 = %@",str3);
//汉字
NSString *str=@"aBCdj34中国";
NSLog(@"str＝%@",str);
NSLog(@"length＝%lu",(unsigned
long)[str length]);//字符长度
NSLog(@"中文占两个字符
length = %lu",(unsigned
long)[str
lengthOfBytesUsingEncoding:NSUTF8StringEncoding]);//字符长度，中文占两个字符
//剔除字符串
NSString *ch1=@" abj87w34 abTRE986 e1J6U";
ch1=[ch1 stringByTrimmingCharactersInSet:[NSCharacterSet
whitespaceCharacterSet]];
//去除首尾空格
NSLog(@"去除首尾空格ch1:%@",ch1);
ch1 = [ch1 stringByTrimmingCharactersInSet:[NSCharacterSet
lowercaseLetterCharacterSet]];
//去除首尾小写字母
NSLog(@"去除首尾小写字母ch1:%@",ch1);
ch1 = [ch1 stringByTrimmingCharactersInSet:[NSCharacterSet
uppercaseLetterCharacterSet]];
//去除首尾大写字母
NSLog(@"去除首尾大写字母ch1:%@",ch1);
ch1 = [ch1 stringByTrimmingCharactersInSet:[NSCharacterSet
characterSetWithCharactersInString:@"87"]];//去除首尾指定字符串
NSLog(@"去除首尾指定字符串ch1:%@",ch1);
//字符串与其它类型值互换
int aa =
123;
float bb =
3.0;
NSString *aaStr = [NSString
stringWithFormat:@"%d---%f",aa+4,bb];
//数值->字符
NSLog(@"aaStr: %@",aaStr);
NSArray *strrArray =
@[@"345",@"342.998"];
int a = [strrArray[0]
intValue]; //字符->数值
float b = [strrArray[1]
floatValue];
NSLog(@"a= %d, b= %.2f",a,b);
//保留两位小数点
}
#pragma mark -动态字符串的增、删、查找、替换、判断
-(void)demo2{
NSMutableString *s1 = [NSMutableString
stringWithFormat:@"%@",@"happy new year!"];
NSMutableString *s2 = [NSMutableString
stringWithCapacity:60];
//定义字符串长度60
[s1 appendString:@" baby!"];
//在末尾追加字符
NSLog(@"s1 = %@",s1);
[s2 appendFormat:@"%@",@"happy birthday!"];
NSLog(@"s2 = %@",s2);
[s2 insertString:@"Baby,"
atIndex:0];
//在指定位置插入字符
NSLog(@"s2 = %@",s2);
[s2 deleteCharactersInRange:NSMakeRange(10,
9)];//删除指定字符
NSLog(@"s2 = %@",s2);
[s2 replaceCharactersInRange:NSMakeRange(5,
5) withString:@"hello"];
//替换指定区域字符
NSLog(@"s2 = %@",s2);
//参数1：目标替换值;参数2：替换成为的值;参数3：类型为默认：NSLiteralSearch;参数4：替换的范围
[s2 replaceOccurrencesOfString:@"b"
withString:@"QQ"
options:NSLiteralSearch
range:NSMakeRange(0,
4)];
NSLog(@"s2 = %@",s2);
[s2 setString:@"hello，baby！"];
//按新字符串替换原字符串
NSLog(@"s2 = %@",s2);
}
#pragma mark -深浅copy
-(void)demo3{
NSString *string1 =
@"Hello work!";
NSString *ss1 = [string1
copy]; //浅copy
NSLog(@"ss1:%@",ss1);
string1 = @"happy new year!";
NSLog(@"ss1:%@",ss1);
NSMutableString *string2 = [string1
mutableCopy]; //深copy
NSLog(@"string2:%@",string2);
NSMutableString *string3 = [string2
copy];//深copy
NSLog(@"string3:%@",string3);
[string2 appendString:@"friend!"];
NSLog(@"string2:%@;string3 = %@",string2,string3);
}
#pragma mark -遍历字符串
-(void)demo4{
//遍历字符串
NSString *string =
@"happy 12345 abc";
NSMutableArray *strArray = [NSMutableArray
array];
NSString *chr;
for (int i =
0; i<string.length; i++) {
chr =[string substringWithRange:NSMakeRange(i,
1)];
[strArray addObject:chr];
}
NSLog(@"strArray:%@",strArray);
//倒序重组字符串
NSMutableString *string1 = [NSMutableString
string];
for (NSInteger i = [strArray
count]; i>0; i--) {
[string1 appendString:strArray[i-1]];
}
NSLog(@"string1:%@",string1);
//数组内容查找、替换
for (int i =
0; i<strArray.count; i++) {
if ([strArray[i]
isEqualToString:@"a"]) {
NSLog(@"strArray[%d]",i);
//位置查找
strArray[i]=@"x";
//替换字母a
NSLog(@"strArray[%d]:%@",i,strArray[i]);
}
}
NSLog(@"strArray:%@",strArray);
}
#pragma mark -路径
-(void)demo5{
//扩展路径
NSString *Path =
@"~/NSData.txt";
NSString *absolutePath = [Path
stringByExpandingTildeInPath];
//沙盒中完整路径
NSLog(@"absolutePath:%@",absolutePath);
NSLog(@"Path:%@",[absolutePath
stringByAbbreviatingWithTildeInPath]);//省略路径
//文件扩展名
NSLog(@"Extension:%@",[Path
pathExtension]);
//扩展名
}
//分割线
#pragma mark -
//分组标识
#pragma mark - 数组创建及基本使用
-(void)demo6{
//遍历字符串
NSString *string =
@"happy 12345 abc";
NSMutableArray *strArray = [NSMutableArray
array];
NSString *chr;
for (int i =
0; i<string.length; i++) {
chr =[string substringWithRange:NSMakeRange(i,
1)];
[strArray addObject:chr];
}
NSLog(@"strArray:%@",strArray);
//获取指定下标的数组元素
NSString *ssttrr = strArray[2];
NSString *ssttrr2 = [strArray
objectAtIndex:2];
NSLog(@"%@,%@",ssttrr,ssttrr2);
//判断数组中有无此元素
BOOL isTure = [strArray
containsObject:@"a"];
NSLog(@"包含a吗
%d",isTure);
//获取索引值
NSInteger index = [strArray
indexOfObject:@"p"];
//存在多个相同值时，返回第一个索引值
NSLog(@"w的索引index：
%lu",index);
NSLog(@"第一个元素: %@",[strArray
firstObject]); //获取第一个元素
NSLog(@"最后一个元素: %@",[strArray
lastObject]); //获取最后一个元素
[strArray addObject:@"w"];//在最后加
[strArray insertObject:@"789"
atIndex:8];//在指定位置插入
[strArray setObject:@"66"
atIndexedSubscript:2];
//用新元素替换在指定位置元素
NSArray *strArr =
@[@"4",@"9",@"7",@"8"];
[strArray addObjectsFromArray:strArr];//在末尾追回数组
// [strArray setArray:strArr]; //用新数组替换
[strArray removeObject:@" "];
//删除空格元素
// [strArray removeAllObjects];//删除所有元素
[strArray replaceObjectAtIndex:9
withObject:@"ui"];
//修改指定位置元素
[strArray exchangeObjectAtIndex:0
withObjectAtIndex:1];
//根据索引交换数组元素
//快速遍历数组1
int i =
0;
for (NSString *str
in strArray) {
NSLog(@"str %d =%@",i,str);
i++;
}
//block方法遍历数组2
按顺序遍历
[strArray enumerateObjectsUsingBlock:^(id
_Nonnull obj, NSUInteger idx,
BOOL * _Nonnull stop) {
NSLog(@"obj:%@,索引idx:%ld",obj,idx);
// 如果索引为6，就停止遍历
if (idx ==
6) {
*stop = YES;
// 利用指针修改外面BOOL变量的值
}
}];
//快速创建数组
NSArray *arr = [@"1,2,3,4,5,6,7,8,9,0"
componentsSeparatedByString:@","];
NSLog(@"arr:%@",arr);
//倒序遍历 NSEnumerationReverse
[arr enumerateObjectsWithOptions:NSEnumerationReverse
usingBlock:^(id
_Nonnull obj,
NSUInteger idx,
BOOL *
_Nonnull stop) {
NSLog(@"NSEnumerationReverse obj:%@,索引idx:%ld",obj,idx);
}];
//同时遍历数组，无序 NSEnumerationConcurrent
[arr enumerateObjectsWithOptions:NSEnumerationConcurrent
usingBlock:^(id
_Nonnull obj,
NSUInteger idx,
BOOL *
_Nonnull stop) {
NSLog(@"NSEnumerationConcurrent obj:%@,索引idx:%ld",obj,idx);
}];
//利用分隔符拼接数组所有元素
NSString *ssAdd = [strArray
componentsJoinedByString:@"---"];
NSLog(@"ssAdd:%@",ssAdd);
//利用分隔符切分成数组
NSArray *newArray = [ssAdd
componentsSeparatedByString:@"--"];
NSLog(@"newArray:%@",newArray);
// 将一个数组写入文件（生成的是一个xml文件）
NSString *path =
@"/Users/liaojianguo/array.txt";
[strArray writeToFile:path
atomically:YES];
// 从文件中读取数组内容（文件有严格的格式要求）
NSArray *array2 = [NSArray
arrayWithContentsOfFile:path];
NSLog(@"array2:%@",array2);
//让数组里所有对象都调用同print方法 注意见最下面
// [strArr makeObjectsPerformSelector:@selector(printArr)];
// [strArr makeObjectsPerformSelector:@selector(printArr:) withObject:self];
}
-(void)printArr:(NSString *)str{
NSLog(@"print ok!%@",str);
}
#pragma mark - 数组排序
-(void)demo7{
NSArray *sortArray = [[NSArray
alloc]
initWithObjects:@"1",@"3",@"4",@"7",@"8",@"2",@"6",@"5",@"13",@"12",@"12",@"20",@"28",@"",nil];
//排序前
NSLog(@"排序前:%@",sortArray);
//第一种
用比较器排序数组 block
NSComparator cmptr = ^(id obj1,
id obj2){
if ([obj1
integerValue] > [obj2
integerValue])//数字比较
{
NSLog(@"NSOrderedDescending %ld",(long)(NSComparisonResult)NSOrderedDescending);
return (NSComparisonResult)NSOrderedDescending;
//返回1
}
if ([obj1
integerValue] < [obj2
integerValue]) {
NSLog(@"%ld",(NSComparisonResult)NSOrderedAscending);
return (NSComparisonResult)NSOrderedAscending;
//返回-1
}
NSLog(@"NSOrderedSame %ld",(NSComparisonResult)NSOrderedSame);
return (NSComparisonResult)NSOrderedSame;//返回0
};
NSComparator cmptr2 = ^(id obj1,
id obj2){
if([[NSString
stringWithFormat:@"%@",obj1]
compare:[NSString
stringWithFormat:@"%@",obj2]
options:NSNumericSearch] >
0)//字符串比较
{
return (NSComparisonResult)NSOrderedDescending;
}
if([[NSString
stringWithFormat:@"%@",obj1]
compare:[NSString
stringWithFormat:@"%@",obj2]
options:NSNumericSearch] <
0)
{
return (NSComparisonResult)NSOrderedAscending;
}
return (NSComparisonResult)NSOrderedSame;
};
//第一种 sortedArrayUsingComparator
NSArray *array1 = [sortArray
sortedArrayUsingComparator:cmptr];
NSLog(@"array1排序后:%@",array1);
NSArray *array111 = [sortArray
sortedArrayUsingComparator:cmptr2];
NSLog(@"array111排序后:%@",array111);
NSArray *array112 = [sortArray
sortedArrayUsingComparator:^NSComparisonResult(id
_Nonnull obj1, id
_Nonnull obj2) {
if ([obj1
integerValue] > [obj2
integerValue])//数字比较
{
NSLog(@"NSOrderedDescending %ld",(long)(NSComparisonResult)NSOrderedDescending);
return (NSComparisonResult)NSOrderedDescending;
//返回1
}
if ([obj1
integerValue] < [obj2
integerValue]) {
NSLog(@"%ld",(NSComparisonResult)NSOrderedAscending);
return (NSComparisonResult)NSOrderedAscending;
//返回-1
}
NSLog(@"NSOrderedSame %ld",(NSComparisonResult)NSOrderedSame);
return (NSComparisonResult)NSOrderedSame;//返回0
}];
NSLog(@"array112排序后:%@",array112);
//第二种
用函数排序数组 sortedArrayUsingFunction
NSArray *array2 =[sortArray
sortedArrayUsingFunction:customSort
context:nil];
NSLog(@"array2排序后:%@",array2);
//第三种
使用描述符类 NSSortDescriptor
[self
demo8];
}
//第二种
用函数排序数组
NSInteger customSort(id obj1,
id obj2,void* context)
{
if ([obj1
integerValue] > [obj2
integerValue]) {
return (NSComparisonResult)NSOrderedDescending;
}
if ([obj1
integerValue] < [obj2
integerValue]) {
return (NSComparisonResult)NSOrderedAscending;
}
return (NSComparisonResult)NSOrderedSame;
}
//用于类排序
-(void)demo8{
Student *student1 = [[Student
alloc]initWithName:@"kittey"
number:@"1001"
score:90];
Student *student2 = [[Student
alloc]initWithName:@"meine"
number:@"1006"
score:94];
Student *student3 = [[Student
alloc]initWithName:@"meiqi"
number:@"1002"
score:92];
Student *student4 = [[Student
alloc]initWithName:@"snoopy"
number:@"1005"
score:94];
Student *student5 = [[Student
alloc]initWithName:@"snoopy"
number:@"1008"
score:98];
Student *student6 = [[Student
alloc]initWithName:@"snoopy"
number:@"1009"
score:94];
NSArray *students =
@[student1,student2,student3,student4,student5,student6];
// 1.先按照成绩进行排序
// 这里的key写的是@property的名称
NSSortDescriptor *scoreDesc = [NSSortDescriptor
sortDescriptorWithKey:@"score"
ascending:YES];
// 2.再按照学号进行排序
NSSortDescriptor *numberDesc = [NSSortDescriptor
sortDescriptorWithKey:@"number"
ascending:YES];
// 3.再按照姓名进行排序
NSSortDescriptor *nameDesc = [NSSortDescriptor
sortDescriptorWithKey:@"name"
ascending:YES];
// 按顺序添加排序描述器
NSArray *descs =
@[scoreDesc,nameDesc,numberDesc];
NSArray *array2 = [students
sortedArrayUsingDescriptors:descs];
for (int i=0; i<array2.count;
i++) {
NSLog(@"array2[%d]:%@ %@ %ld", i,[array2[i]
name],[array2[i]
number],[array2[i] score]);
}
}
新建类
#import "ViewController.h"
@interface NSString (MD5Digest)
-(void)printArr:(id)data;
-(void)printArr;
@end
@implementation NSString (MD5)
-(void)printArr:(id)data{
NSLog(@"print ok! %@,%@",self,data);
}
-(void)printArr{
NSLog(@"print ok!");
}
@end
@interface
ViewController ()
@end
@implementation ViewController
- (void)viewDidLoad {
[super
viewDidLoad];
NSArray *strArr=
@[@"sdf",@"sd"];
//让数组里所有对象都调用同print方法
[strArr makeObjectsPerformSelector:@selector(printArr)];
[strArr makeObjectsPerformSelector:@selector(printArr:)
withObject:self];
}
- (void)viewDidLoad {
[super
viewDidLoad];
// [self demo1]; //字符串的拼接、比较、搜索、大小写互换，判断开头与结尾、抽取、互换、剔除
// [self demo2]; //动态字符串的增、删、查找、替换、判断
// [self demo3]; //深浅copy
// [self demo4];//遍历字符串、数组中内容查找
// [self demo5]; //完整路径，省略路径，扩展名
// [self demo6];//数组使用
[self
demo7];//数组排序
}
#pragma mark -字符串的拼接、比较、搜索、大小写互换，判断开头与结尾、抽取、互换、剔除首尾
-(void)demo1{
//赋值
NSString *string =
@"Hello work!";
NSString *string1 =
@"Hello work!";
NSString *string2 =
@"Hello jianguo!";
NSLog(@"string1 = %@ ;string2 = %@",string1,string2);
//拼接
NSString *string3 = [NSString
stringWithFormat:@"%@%@",string1,string2];
NSLog(@"string3 = %@",string3);
//比较
if ([string1
isEqualToString:string2])
//区分大小写的
{
NSLog(@"YES");
}else{
NSLog(@"NO");
}
//compare
BOOL result = ([string1
compare:string2] ==
NSOrderedSame); //NSOrderedSame判断两者内容是否相同
result = [string1 compare:string] ==
NSOrderedSame;
NSLog(@"result = %d",result);
result = [string1 compare:string2] ==
NSOrderedAscending;
//按字母比较，string2大于string1为真
NSLog(@"result = %d",result);
result = [string1 compare:string2] ==
NSOrderedDescending;
//按字母比较，string2小于string1为真
NSLog(@"result = %d",result);
NSString *string4 =
@"hello work!";
result = [string1 caseInsensitiveCompare:string4] ==
NSOrderedSame; //不考虑大小写比较
NSLog(@"result = %d",result);
result = [string1 compare:string2
options:NSCaseInsensitiveSearch |NSNumericSearch]
== NSOrderedSame;
//NSCaseInsensitiveSearch 不区分大小写;NSNumericSearch比较字符串的个数，不比较内容;NSLiteralSearch
区分大小写
NSLog(@"NSCaseInsensitiveSearch result = %d",result);
//大小写转换
NSLog(@"%@:%@",string1,[string1
uppercaseString]);
//大写
NSLog(@"%@:%@",string1,[string1
lowercaseString]);//小写
NSLog(@"%@:%@",string4,[string4
capitalizedString]);//单词首字母大写
//在字符串中搜索字串
NSRange rang = [string3
rangeOfString:string1];
NSLog(@"string3 = %@,string1 = %@",string3,string1);
NSLog(@"location = %ld,length = %ld",rang.location,rang.length);
//子串string1在string3中的位置和长度
//hasPrefix 判断开头
result = [string3 hasPrefix:string1];//判断string3是否以string1开头
result = [string3 hasPrefix:string2];
NSLog(@"hasPrefix result = %d",result);
//hasSuffix 判断结尾
result = [string3 hasSuffix:string2];
NSLog(@"hasSuffix result = %d",result);
//抽取字符串
NSString *str1 = [string3
substringFromIndex:3];//从索引位置截取到最后
NSLog(@"str1 = %@",str1);
NSString *str2 = [string3
substringToIndex:8];
//从开始截取到索引位置
NSLog(@"str2 = %@",str2);
NSString *str3 = [string3
substringWithRange:NSMakeRange(6,
6)];
NSLog(@"str3 = %@",str3);
//汉字
NSString *str=@"aBCdj34中国";
NSLog(@"str＝%@",str);
NSLog(@"length＝%lu",(unsigned
long)[str length]);//字符长度
NSLog(@"中文占两个字符
length = %lu",(unsigned
long)[str
lengthOfBytesUsingEncoding:NSUTF8StringEncoding]);//字符长度，中文占两个字符
//剔除字符串
NSString *ch1=@" abj87w34 abTRE986 e1J6U";
ch1=[ch1 stringByTrimmingCharactersInSet:[NSCharacterSet
whitespaceCharacterSet]];
//去除首尾空格
NSLog(@"去除首尾空格ch1:%@",ch1);
ch1 = [ch1 stringByTrimmingCharactersInSet:[NSCharacterSet
lowercaseLetterCharacterSet]];
//去除首尾小写字母
NSLog(@"去除首尾小写字母ch1:%@",ch1);
ch1 = [ch1 stringByTrimmingCharactersInSet:[NSCharacterSet
uppercaseLetterCharacterSet]];
//去除首尾大写字母
NSLog(@"去除首尾大写字母ch1:%@",ch1);
ch1 = [ch1 stringByTrimmingCharactersInSet:[NSCharacterSet
characterSetWithCharactersInString:@"87"]];//去除首尾指定字符串
NSLog(@"去除首尾指定字符串ch1:%@",ch1);
//字符串与其它类型值互换
int aa =
123;
float bb =
3.0;
NSString *aaStr = [NSString
stringWithFormat:@"%d---%f",aa+4,bb];
//数值->字符
NSLog(@"aaStr: %@",aaStr);
NSArray *strrArray =
@[@"345",@"342.998"];
int a = [strrArray[0]
intValue]; //字符->数值
float b = [strrArray[1]
floatValue];
NSLog(@"a= %d, b= %.2f",a,b);
//保留两位小数点
}
#pragma mark -动态字符串的增、删、查找、替换、判断
-(void)demo2{
NSMutableString *s1 = [NSMutableString
stringWithFormat:@"%@",@"happy new year!"];
NSMutableString *s2 = [NSMutableString
stringWithCapacity:60];
//定义字符串长度60
[s1 appendString:@" baby!"];
//在末尾追加字符
NSLog(@"s1 = %@",s1);
[s2 appendFormat:@"%@",@"happy birthday!"];
NSLog(@"s2 = %@",s2);
[s2 insertString:@"Baby,"
atIndex:0];
//在指定位置插入字符
NSLog(@"s2 = %@",s2);
[s2 deleteCharactersInRange:NSMakeRange(10,
9)];//删除指定字符
NSLog(@"s2 = %@",s2);
[s2 replaceCharactersInRange:NSMakeRange(5,
5) withString:@"hello"];
//替换指定区域字符
NSLog(@"s2 = %@",s2);
//参数1：目标替换值;参数2：替换成为的值;参数3：类型为默认：NSLiteralSearch;参数4：替换的范围
[s2 replaceOccurrencesOfString:@"b"
withString:@"QQ"
options:NSLiteralSearch
range:NSMakeRange(0,
4)];
NSLog(@"s2 = %@",s2);
[s2 setString:@"hello，baby！"];
//按新字符串替换原字符串
NSLog(@"s2 = %@",s2);
}
#pragma mark -深浅copy
-(void)demo3{
NSString *string1 =
@"Hello work!";
NSString *ss1 = [string1
copy]; //浅copy
NSLog(@"ss1:%@",ss1);
string1 = @"happy new year!";
NSLog(@"ss1:%@",ss1);
NSMutableString *string2 = [string1
mutableCopy]; //深copy
NSLog(@"string2:%@",string2);
NSMutableString *string3 = [string2
copy];//深copy
NSLog(@"string3:%@",string3);
[string2 appendString:@"friend!"];
NSLog(@"string2:%@;string3 = %@",string2,string3);
}
#pragma mark -遍历字符串
-(void)demo4{
//遍历字符串
NSString *string =
@"happy 12345 abc";
NSMutableArray *strArray = [NSMutableArray
array];
NSString *chr;
for (int i =
0; i<string.length; i++) {
chr =[string substringWithRange:NSMakeRange(i,
1)];
[strArray addObject:chr];
}
NSLog(@"strArray:%@",strArray);
//倒序重组字符串
NSMutableString *string1 = [NSMutableString
string];
for (NSInteger i = [strArray
count]; i>0; i--) {
[string1 appendString:strArray[i-1]];
}
NSLog(@"string1:%@",string1);
//数组内容查找、替换
for (int i =
0; i<strArray.count; i++) {
if ([strArray[i]
isEqualToString:@"a"]) {
NSLog(@"strArray[%d]",i);
//位置查找
strArray[i]=@"x";
//替换字母a
NSLog(@"strArray[%d]:%@",i,strArray[i]);
}
}
NSLog(@"strArray:%@",strArray);
}
#pragma mark -路径
-(void)demo5{
//扩展路径
NSString *Path =
@"~/NSData.txt";
NSString *absolutePath = [Path
stringByExpandingTildeInPath];
//沙盒中完整路径
NSLog(@"absolutePath:%@",absolutePath);
NSLog(@"Path:%@",[absolutePath
stringByAbbreviatingWithTildeInPath]);//省略路径
//文件扩展名
NSLog(@"Extension:%@",[Path
pathExtension]);
//扩展名
}
//分割线
#pragma mark -
//分组标识
#pragma mark - 数组创建及基本使用
-(void)demo6{
//遍历字符串
NSString *string =
@"happy 12345 abc";
NSMutableArray *strArray = [NSMutableArray
array];
NSString *chr;
for (int i =
0; i<string.length; i++) {
chr =[string substringWithRange:NSMakeRange(i,
1)];
[strArray addObject:chr];
}
NSLog(@"strArray:%@",strArray);
//获取指定下标的数组元素
NSString *ssttrr = strArray[2];
NSString *ssttrr2 = [strArray
objectAtIndex:2];
NSLog(@"%@,%@",ssttrr,ssttrr2);
//判断数组中有无此元素
BOOL isTure = [strArray
containsObject:@"a"];
NSLog(@"包含a吗
%d",isTure);
//获取索引值
NSInteger index = [strArray
indexOfObject:@"p"];
//存在多个相同值时，返回第一个索引值
NSLog(@"w的索引index：
%lu",index);
NSLog(@"第一个元素: %@",[strArray
firstObject]); //获取第一个元素
NSLog(@"最后一个元素: %@",[strArray
lastObject]); //获取最后一个元素
[strArray addObject:@"w"];//在最后加
[strArray insertObject:@"789"
atIndex:8];//在指定位置插入
[strArray setObject:@"66"
atIndexedSubscript:2];
//用新元素替换在指定位置元素
NSArray *strArr =
@[@"4",@"9",@"7",@"8"];
[strArray addObjectsFromArray:strArr];//在末尾追回数组
// [strArray setArray:strArr]; //用新数组替换
[strArray removeObject:@" "];
//删除空格元素
// [strArray removeAllObjects];//删除所有元素
[strArray replaceObjectAtIndex:9
withObject:@"ui"];
//修改指定位置元素
[strArray exchangeObjectAtIndex:0
withObjectAtIndex:1];
//根据索引交换数组元素
//快速遍历数组1
int i =
0;
for (NSString *str
in strArray) {
NSLog(@"str %d =%@",i,str);
i++;
}
//block方法遍历数组2
按顺序遍历
[strArray enumerateObjectsUsingBlock:^(id
_Nonnull obj, NSUInteger idx,
BOOL * _Nonnull stop) {
NSLog(@"obj:%@,索引idx:%ld",obj,idx);
// 如果索引为6，就停止遍历
if (idx ==
6) {
*stop = YES;
// 利用指针修改外面BOOL变量的值
}
}];
//快速创建数组
NSArray *arr = [@"1,2,3,4,5,6,7,8,9,0"
componentsSeparatedByString:@","];
NSLog(@"arr:%@",arr);
//倒序遍历 NSEnumerationReverse
[arr enumerateObjectsWithOptions:NSEnumerationReverse
usingBlock:^(id
_Nonnull obj,
NSUInteger idx,
BOOL *
_Nonnull stop) {
NSLog(@"NSEnumerationReverse obj:%@,索引idx:%ld",obj,idx);
}];
//同时遍历数组，无序 NSEnumerationConcurrent
[arr enumerateObjectsWithOptions:NSEnumerationConcurrent
usingBlock:^(id
_Nonnull obj,
NSUInteger idx,
BOOL *
_Nonnull stop) {
NSLog(@"NSEnumerationConcurrent obj:%@,索引idx:%ld",obj,idx);
}];
//利用分隔符拼接数组所有元素
NSString *ssAdd = [strArray
componentsJoinedByString:@"---"];
NSLog(@"ssAdd:%@",ssAdd);
//利用分隔符切分成数组
NSArray *newArray = [ssAdd
componentsSeparatedByString:@"--"];
NSLog(@"newArray:%@",newArray);
// 将一个数组写入文件（生成的是一个xml文件）
NSString *path =
@"/Users/liaojianguo/array.txt";
[strArray writeToFile:path
atomically:YES];
// 从文件中读取数组内容（文件有严格的格式要求）
NSArray *array2 = [NSArray
arrayWithContentsOfFile:path];
NSLog(@"array2:%@",array2);
//让数组里所有对象都调用同print方法 注意见最下面
// [strArr makeObjectsPerformSelector:@selector(printArr)];
// [strArr makeObjectsPerformSelector:@selector(printArr:) withObject:self];
}
-(void)printArr:(NSString *)str{
NSLog(@"print ok!%@",str);
}
#pragma mark - 数组排序
-(void)demo7{
NSArray *sortArray = [[NSArray
alloc]
initWithObjects:@"1",@"3",@"4",@"7",@"8",@"2",@"6",@"5",@"13",@"12",@"12",@"20",@"28",@"",nil];
//排序前
NSLog(@"排序前:%@",sortArray);
//第一种
用比较器排序数组 block
NSComparator cmptr = ^(id obj1,
id obj2){
if ([obj1
integerValue] > [obj2
integerValue])//数字比较
{
NSLog(@"NSOrderedDescending %ld",(long)(NSComparisonResult)NSOrderedDescending);
return (NSComparisonResult)NSOrderedDescending;
//返回1
}
if ([obj1
integerValue] < [obj2
integerValue]) {
NSLog(@"%ld",(NSComparisonResult)NSOrderedAscending);
return (NSComparisonResult)NSOrderedAscending;
//返回-1
}
NSLog(@"NSOrderedSame %ld",(NSComparisonResult)NSOrderedSame);
return (NSComparisonResult)NSOrderedSame;//返回0
};
NSComparator cmptr2 = ^(id obj1,
id obj2){
if([[NSString
stringWithFormat:@"%@",obj1]
compare:[NSString
stringWithFormat:@"%@",obj2]
options:NSNumericSearch] >
0)//字符串比较
{
return (NSComparisonResult)NSOrderedDescending;
}
if([[NSString
stringWithFormat:@"%@",obj1]
compare:[NSString
stringWithFormat:@"%@",obj2]
options:NSNumericSearch] <
0)
{
return (NSComparisonResult)NSOrderedAscending;
}
return (NSComparisonResult)NSOrderedSame;
};
//第一种 sortedArrayUsingComparator
NSArray *array1 = [sortArray
sortedArrayUsingComparator:cmptr];
NSLog(@"array1排序后:%@",array1);
NSArray *array111 = [sortArray
sortedArrayUsingComparator:cmptr2];
NSLog(@"array111排序后:%@",array111);
NSArray *array112 = [sortArray
sortedArrayUsingComparator:^NSComparisonResult(id
_Nonnull obj1, id
_Nonnull obj2) {
if ([obj1
integerValue] > [obj2
integerValue])//数字比较
{
NSLog(@"NSOrderedDescending %ld",(long)(NSComparisonResult)NSOrderedDescending);
return (NSComparisonResult)NSOrderedDescending;
//返回1
}
if ([obj1
integerValue] < [obj2
integerValue]) {
NSLog(@"%ld",(NSComparisonResult)NSOrderedAscending);
return (NSComparisonResult)NSOrderedAscending;
//返回-1
}
NSLog(@"NSOrderedSame %ld",(NSComparisonResult)NSOrderedSame);
return (NSComparisonResult)NSOrderedSame;//返回0
}];
NSLog(@"array112排序后:%@",array112);
//第二种
用函数排序数组 sortedArrayUsingFunction
NSArray *array2 =[sortArray
sortedArrayUsingFunction:customSort
context:nil];
NSLog(@"array2排序后:%@",array2);
//第三种
使用描述符类 NSSortDescriptor
[self
demo8];
}
//第二种
用函数排序数组
NSInteger customSort(id obj1,
id obj2,void* context)
{
if ([obj1
integerValue] > [obj2
integerValue]) {
return (NSComparisonResult)NSOrderedDescending;
}
if ([obj1
integerValue] < [obj2
integerValue]) {
return (NSComparisonResult)NSOrderedAscending;
}
return (NSComparisonResult)NSOrderedSame;
}
//用于类排序
-(void)demo8{
Student *student1 = [[Student
alloc]initWithName:@"kittey"
number:@"1001"
score:90];
Student *student2 = [[Student
alloc]initWithName:@"meine"
number:@"1006"
score:94];
Student *student3 = [[Student
alloc]initWithName:@"meiqi"
number:@"1002"
score:92];
Student *student4 = [[Student
alloc]initWithName:@"snoopy"
number:@"1005"
score:94];
Student *student5 = [[Student
alloc]initWithName:@"snoopy"
number:@"1008"
score:98];
Student *student6 = [[Student
alloc]initWithName:@"snoopy"
number:@"1009"
score:94];
NSArray *students =
@[student1,student2,student3,student4,student5,student6];
// 1.先按照成绩进行排序
// 这里的key写的是@property的名称
NSSortDescriptor *scoreDesc = [NSSortDescriptor
sortDescriptorWithKey:@"score"
ascending:YES];
// 2.再按照学号进行排序
NSSortDescriptor *numberDesc = [NSSortDescriptor
sortDescriptorWithKey:@"number"
ascending:YES];
// 3.再按照姓名进行排序
NSSortDescriptor *nameDesc = [NSSortDescriptor
sortDescriptorWithKey:@"name"
ascending:YES];
// 按顺序添加排序描述器
NSArray *descs =
@[scoreDesc,nameDesc,numberDesc];
NSArray *array2 = [students
sortedArrayUsingDescriptors:descs];
for (int i=0; i<array2.count;
i++) {
NSLog(@"array2[%d]:%@ %@ %ld", i,[array2[i]
name],[array2[i]
number],[array2[i] score]);
}
}
新建类
#import "ViewController.h"
@interface NSString (MD5Digest)
-(void)printArr:(id)data;
-(void)printArr;
@end
@implementation NSString (MD5)
-(void)printArr:(id)data{
NSLog(@"print ok! %@,%@",self,data);
}
-(void)printArr{
NSLog(@"print ok!");
}
@end
@interface
ViewController ()
@end
@implementation ViewController
- (void)viewDidLoad {
[super
viewDidLoad];
NSArray *strArr=
@[@"sdf",@"sd"];
//让数组里所有对象都调用同print方法
[strArr makeObjectsPerformSelector:@selector(printArr)];
[strArr makeObjectsPerformSelector:@selector(printArr:)
withObject:self];
}
内容来自用户分享和网络整理，不保证内容的准确性，如有侵权内容，可联系管理员处理 
相关文章推荐
- Objective-C的内省(Introspection)用法小结
- Objective-C中常用的结构体NSRange,NSPoint,NSSize(CGSize),NSRect实例分析
- Objective-C中使用NSString类操作字符串的方法小结
- Objective-C中NSNumber与NSDictionary的用法简介
- Objective-C中NSLog输出格式大全
- Objective-C实现自定义的半透明导航
- 浅析Objective-C的程序结构及面向对象的编程方式
- Objective-C的入门学习笔记
- Objective-C实现无限循环轮播器
- 全面解析Objective-C中的block代码块的使用
- Swift调用Objective-C编写的API实例
- Swift、Objective-C、Cocoa混合编程设置指南
- Objective-c代码如何移植为Swift代码 Objective-c代码转移到Swift过程介绍
- Swift调用Objective-C代码
- Objective-C中字符串NSString的常用操作方法总结
- 以实例讲解Objective-C中的KVO与KVC机制
- 简介Objective-C解析XML与JSON数据格式的方法
- 浅析Objective-C中分类Category的使用
- 举例讲解Objective-C中@property属性的用法
- Objective-C编程中语句和变量的一些编写规范建议