iOS之字符串处理:截取字符串、匹配字符串、分隔字符串

1、字符串的截取

//1.截取字符串
    
NSString *string =@"123456d890";
NSString *str1 = [string substringToIndex:5];//截取掉下标5之前的字符串
NSLog(@"截取的值为：%@",str1);
 NSString *str2 = [string substringFromIndex:3];//截取掉下标3之后的字符串
NSLog(@"截取的值为：%@",str2);

2、匹配字符串  从字符串(sd是sfsfsAdfsdf)中查找(匹配)字符串(Ad)

//2.匹配字符串
NSString *string =@"sd是sfsfsAdfsdf";
NSRange range = [string rangeOfString:@"Ad"];//匹配得到的下标
NSLog(@"rang:%@",NSStringFromRange(range));
string = [string substringWithRange:range];//截取范围内的字符串
NSLog(@"截取的值为：%@",string);

3、字符串分割  根据字符串中的某个字符(A)来分割字符串

//3.分隔字符串
NSString *string =@"sdfsfsfsAdfsdf";
    
NSArray *array = [string componentsSeparatedByString:@"A"]; //从字符A中分隔成2个元素的数组
NSLog(@"array:%@",array); //结果是adfsfsfs和dfsdf

4、字符串 截取开始索引到匹配字符所在索引 

NSString *result = @"{849389402324859:,,4548548}000000000000000";
NSString *temp = nil;
int lastIndex = 0;
for(int i =0; i < [result length]; i++){
    temp = [result substringWithRange:NSMakeRange(i, 1)];
    if ([temp isEqualToString:@"}"]){
        NSLog(@"第%d个字是:%@", i, temp);
        lastIndex = i;
    }
}
result = [result substringWithRange:NSMakeRange(0, lastIndex + 1)]; //从开始截取到最后一个“}”
NSLog(@"result：%@",result);