NSString的各种操作,拼接、搜索、截取

//
//  main.m
//  NSString
//
//  Created by WildCat on 13-7-25.
//  Copyright (c) 2013年 wildcat. All rights reserved.
//

#import <Foundation/Foundation.h>
#pragma mark 创建字符串
void testCreat(){
NSString *str=@"你好。";
NSLog(@"str :%@",str);

NSString *str2=[NSString stringWithUTF8String:"哈哈哈"];
NSLog(@"str2 :%@",str2);
NSString *str3=[[NSString alloc] initWithString:@"测试3"] ;
NSLog(@"str3 :%@",str3);

}

#pragma mark 字符串的搜索
void search(){

NSString *str=@"123456456.txt";
NSLog(@"是否以 123 开头:%i",[str hasPrefix:@"123"]);
NSLog(@"是否以 txt 结尾:%i",[str hasSuffix:@"txt"]);

//从前向后搜索
NSRange range=[str rangeOfString:@"456"];

if (range.location==NSNotFound) {
NSLog(@"未找到");
}else{
NSLog(@"找到的范围是：%@",NSStringFromRange(range));

}
//从后向前搜索
range=[str rangeOfString:@"456" options:NSBackwardsSearch ];
NSLog(@"找到的范围是：%@",NSStringFromRange(range));

}

#pragma mark 字符串截取
void mysubString(){

NSString *str=@"123456789";
//从第6个位置开始截取
NSLog(@"%@",[str substringFromIndex:6]);
//截取到第6个位置
NSLog(@"%@",[str substringToIndex:6]);
//随便截取一段字符串
NSLog(@"%@",[str substringWithRange:NSMakeRange(1, 3)]);

NSString *str2=@"1-2-a-b-c";
//字符串分割
NSArray *array=[str2 componentsSeparatedByString:@"-"];
NSLog(@"%@",array);
}
#pragma mark 与路径相关
void stringWithPath(){

//快速创建一个自动释放的数组
NSMutableArray *array=[NSMutableArray array];
[array addObject:@"User"];
[array addObject:@"Wildcat"];
[array addObject:@"APP"];
//通过一个数组创建一个路径字符串
NSString *path=[NSString pathWithComponents:array];
NSLog(@"Path is:%@",path);
//把一个路径截取为数组
NSArray *apath=[path pathComponents];
NSLog(@"Array is；%@",apath);

//删除最后一个目录

NSLog(@"Array is；%@",[path stringByDeletingLastPathComponent]);
//拼接一个路径
NSLog(@"Array is；%@",[path stringByAppendingPathComponent:@"123.txt"]);

}

#pragma mark 其他用法

void other(){
NSString *str=@"123";
int a=[str intValue];//转化为整数
NSLog(@"%i",a);
//计算字数而不是字符数
NSLog(@"length=%zi",[@"我是字符串12345" length]);
//返回对应的字符
unichar c=[@"abc123" characterAtIndex:1];
NSLog(@"第2个字符是：%c",c);

//返回C语言字符串
const char *s=[@"abc" UTF8String];
NSLog(@"C语言字符串是：%s",s);

}

#pragma mark 主函数
int main(int argc, const char * argv[])
{

@autoreleasepool {

// testCreat();
// creatWithContent();
//writeToFile();
//search();
//调用截取字符串函数
//mysubString();
//stringWithPath();
other();
}
return 0;
}