将“文艺青年”改成“213青年”

//2.将“文艺青年”改成“213青年”。

//方法1

NSString *str1 = @"文艺青年";

NSString *str2 = [str1  stringByReplacingOccurrencesOfString:@"文艺" withString:@"213" ];

NSLog(@"%@",str2);

//方法2

NSString *str1 = @"文艺青年";

NSString *str2  = [str1 stringByReplacingCharactersInRange:NSMakeRange(0, 2) withString:@"213"];

NSLog(@"%@",str2);

//方法3

NSMutableString *str1 = [NSMutableString stringWithFormat:@"文艺青年" ];

[str1 deleteCharactersInRange:NSMakeRange(0, 2)];

[str1 insertString:@"213" atIndex:0];

NSLog(@"%@",str1);

//方法4

NSMutableString *str1 = [NSMutableString stringWithFormat:@"文艺青年"];

[str1 setString:@"213青年"];

NSLog(@"%@",str1);

将“文艺青年”改成“213青年”