iOS 字符串处理：截取字符串、匹配字符串、分割字符串、

1.截取字符串

NSString *string =@"sdfsfsfsAdfsdf";
string = [string substringToIndex:7];//截取掉下标7之后的字符串
NSLog(@"截取的值为：%@",string);
[string substringFromIndex:2];//截取掉下标2之前的字符串
NSLog(@"截取的值为：%@",string);


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 = [string componentsSeparatedByString:@"A"]; //
NSString *str1 = [array objectAtIndex:0];
NSString *str2 = [array objectAtIndex:1];
从字符A中分隔成2个元素的数组
NSLog(@"array:%@",array); //结果是adfsfsfs和dfsdf

若获取某指定字符串，可重复使用第三步分割字符串进行分割知道
获取想要的

NSString *string =@"sdfsfsfsAdfsdf";
NSArray  *array = [string componentsSeparatedByString:@"A"]; //
NSString *str1 = [array objectAtIndex:0];
NSString *str2 = [array objectAtIndex:1];

NSArray  *str1 = [string componentsSeparatedByString:@"X"]; //自定义
NSString *string1 = [array objectAtIndex:0];
NSString *string2 = [array objectAtIndex:1];