字符串截取

1.截取字符串

NSString*string =@"iPhone";

string = [string substringToIndex:2];//截取掉下标2之后的字符串

NSLog(@"截取的值为：%@",string);  //iP

[string substringFromIndex:2];//截取掉下标2之前的字符串

NSLog(@"截取的值为：%@",string);  //hone

2.匹配字符串

NSString*string =@"sdfsfsfsAdfsdf";

NSRangerange = [stringrangeOfString:@"f"];//匹配得到的下标

NSLog(@"rang:%@",NSStringFromRange(range));

string = [string substringWithRange:range];//截取范围类的字符串

NSLog(@"截取的值为：%@",string);

3.分隔字符串

NSString*string =@"sdfsfsfsAdfsdf";

NSArray *array = [str componentsSeparatedByString:@","];

//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.判断字符串中是否包含某个字符串

if([urlStr rangeOfString:@"plist"].location== NSNotFound) {               

   [self.isDownArrayaddObject:urlStr];            

}

5.数组转字符串

NSString *ns=[array componentsJoinedByString:@",”];

6.数组倒序

如果数组中装的是1，2，3，4经过reverseObjectEnumerator处理后，数组中各个元素会倒序排列，结果为4，3，2，1.

 _dataArray=(NSMutableArray *)[[_dataArray reverseObjectEnumerator] allObjects];