1 //定义一个可变字符串, Format后面可以跟字符串类型,也可以传入C语言的字符串数组
2 NSMutableString *str = [NSMutableString stringWithFormat:@"<#NSString#>"];
3
4 // 获取NSMutableString或NString 某位置的字符
5 NSMutableString *newS1=[NSMutableString stringWithString:s1];
6 for (int i = 0; i<s1.length; i++) {
7 char c1 = [newS1 characterAtIndex:i]; // 用c1去接收了newS1 i 位置的字符
8 }
9
10 //初始化一个NSArray
11 NSMutableArray *arr = [NSMutableArray array];
12 //给数组arr增加元素
13 [arr addObject:xxx]
14
15 //定义一个字典
16 NSMutableDictionary *dict1 = [NSMutableDictionary dictionaryWithDictionary:@{<#@"k1":@"v1",@"k2":@"v2"#>}];
17
18 // 替换字符串
19 NSMutableString *str = [NSMutableString stringWithFormat:@"123iositheimaios"];
20 NSString *newStr = [str stringByReplacingOccurrencesOfString:@"ios" withString:@"andriod"];
21
22 // 去空格
23 +(NSString *)removeSpace:(NSString *)s{
24 NSString *newStr = [s stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]];
25 return newStr;
26 }
27
28 // 字符串反转
29 unsigned long len = str.length;
30 NSMutableString *newStr;
31 for (unsigned long i=len; i>0; i--) {
32 [newStr appendString:[str substringWithRange:NSMakeRange(i-1, 1)]];
33 }
34 return newStr;