字符串的增删改查

iOS 开发中一些字符串的处理

增:

NSMutableString *str = [[NSMutableString alloc] init];

    

    [str appendString:@"20161212"];

    

    [str insertString:@"-" atIndex:4];

    [str insertString:@"-" atIndex:7];

    NSLog(@"%@", str);//2016-12-12

//    1, 新建一个 NSMutableString 的对象

    NSMutableString *str1 = [[NSMutableString alloc] init];

    // 获得的是空字符串

    

    // 2, 追加数据

    [str1 appendString:@"123"];

    

    [str1 appendString:@"456"];

    

    NSLog(@"|%@|", str);//123456

删:

 NSMutableString *s4 = [[NSMutableString alloc] init];

    [s4 appendString:@"0123456789"];

     

    [s4 deleteCharactersInRange:NSMakeRange(3, 3)];

     NSLog(@"%@", s4);//01236789

改:

1.NSString *str = @"123456712345671234567";

    // 1 -> 壹

    // 重新生成一个新的字符串

    NSString *str2 = [str stringByReplacingOccurrencesOfString:@"1" withString:@"壹"];//替换

    NSLog(@"%@", str2);

2.NSString *str3 = @"    abc    ";

    NSLog(@"|%@|", str3);

    // 去掉首尾空格

    str3 = [str3 stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];

3.NSString *str4 = @"121121131";

    // 将两边的 1 去掉

    NSRange range = {3,2};

    str4 = [str4 stringByTrimmingCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@"1"]];

    str4 = [str4 stringByTrimmingCharactersInSet:[NSCharacterSet characterSetWithRange:range]];

    NSLog(@"|%@|", str4);

// 替换

    NSMutableString *s6 = [NSMutableString stringWithString:@"0123456789"];

    

    [s6 replaceCharactersInRange:NSMakeRange(3, 3) withString:@"3"];

    

    NSLog(@"%@", s6);