Objective-C Foundation框架实践——NSString（三）

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {
@autoreleasepool {

//////////////////////////////////////////////////////////////////////

//判断两个字符串是否相同；
NSString *string1 = @"Hello World";
BOOL ss = [string1 isEqualToString:@"A"];
NSLog(@"%hhd",ss);

//比较字符串
/*
NSComparisonResult的结果是一个枚举类型，

enum {
NSOrderedAscending = -1,
NSOrderedSame,
NSOrderedDescending
};
typedef NSInteger NSComparisonResult;

NSOrderedAscending：坐标的字符串比右边的小；-1
NSOrderedSame：左右的字符串相等；0
NSOrderedDescending：左边的字符串比右边的大；1

*/
NSComparisonResult result = [string1 compare:@"B"];
NSLog(@"比较字符串 %ld",(long)result);

//分割；
//按照指定字符分割字符分割字符串；
NSString *string2 = @"a,b,c,d,e,f,g";
NSArray *array = [string2 componentsSeparatedByString:@","];

//遍历数组中的每一个字符；
for (NSString *s in array) {
NSLog(@"%@",s);
}

//按照范围截取字符串；
NSString *string3 = @"abcdefgh";
NSRange range = NSMakeRange(0, 3);
NSString *string4 = [string3 substringWithRange:range];//使用范围去截取一个字符串
NSLog(@"string4 = %@",string4);

//从某一位开始截取字符串到最后一位；
NSString *string5 = [string3 substringFromIndex:3];
NSLog(@"string5 = %@",string5);

//从开头截取字符串到某一位；截取到某一位之前；
NSString *string6 = [string3 substringToIndex:3];
NSLog(@"string6 = %@",string6);

//将字符串拆分为每一个字符；
for (int i = 0 ; i < string3.length ; i++) {
//返回的是一个字符；
NSLog(@"%c",[string3 characterAtIndex:i]);
}

//查找
NSString *string7 = @"ab cd ef gh ij kl";
//查找指定字符串的位置；
NSRange range2 = [string7 rangeOfString:@"ef"];
NSLog(@"length = %lu; location = %lu",(unsigned long)range2.length,(unsigned long)range2.location);

//替换
NSString *string8 = @"ab cd ef gh ij kl";
NSString *string9 = [string8 stringByReplacingOccurrencesOfString:@"gh" withString:@"Hello"];
NSLog(@"string9 = %@",string9);

NSString *string10 = [string8 stringByReplacingCharactersInRange:NSMakeRange(3, 2) withString:@"iOS"];
NSLog(@"string10 = %@",string10);

return 0;
}
}