NSMutableString常用方法

1.NSMutableString常用方法

• - (void)appendString:(NSString *)aString;
  • 拼接aString到最后面

 　　NSMutableString *strM = [NSMutableString string];
    NSLog(@"strM = %@", strM);
    [strM appendString:@"lnj"];
    NSLog(@"strM = %@", strM);

• - (void)appendFormat:(NSString *)format, ...;
  • 拼接一段格式化字符串到最后面

NSMutableString *strM = [NSMutableString string];
[strM appendFormat:@"/age is %i", 10];

• - (void)deleteCharactersInRange:(NSRange)range;
  • 删除range范围内的字符串

 NSMutableString *strM = [NSMutableString stringWithString:@"http://www.520it.com"];
     // 一般情况下利用rangeOfString和deleteCharactersInRange配合删除指定内容
     NSRange range = [strM rangeOfString:@"http://"];
     [strM deleteCharactersInRange:range];
     NSLog(@"strM = %@", strM);

• - (void)insertString:(NSString *)aString atIndex:(NSUInteger)loc;
  • 在loc这个位置中插入aString

 NSMutableString *strM = [NSMutableString stringWithString:@"www.520it.com"];
    [strM insertString:@"http://" atIndex:0];
    NSLog(@"strM = %@", strM);

• - (void)replaceCharactersInRange:(NSRange)range withString:(NSString *)aString;
  • 使用aString替换range范围内的字符串

    NSMutableString *strM = [NSMutableString stringWithString:@"http://www.520it.com/lnj.png"];
    NSRange range = [strM rangeOfString:@"lnj"];
    [strM replaceOccurrencesOfString:@"lnj" withString:@"jjj" options:0 range:range];
    NSLog(@"strM = %@", strM);

2.字符串使用注意事项

• @”lnj”这种方式创建的字符串始终是NSString,不是NSMutalbeString.所以下面的代码创建的还是NSString,此时使用可变字符串的函数,无法操作字符串。

NSMutalbeString *s1 = @”lnj”;
// 会报错
[strM insertString:@"my name is " atIndex:0];