foundation 框架 NSString常用总结(二)

以此作为NSString常用总结（一）的补充

 1 　　　　　NSString* str = [NSString stringWithFormat:@"I love programing! You, come here"];
 2         //字符串对象的大小写转换
 3         //转换为大写
 4         NSString* upStr = [str uppercaseString];
 5         NSLog(@"str = %@", str);
 6         NSLog(@"upStr = %@", upStr);
 7         //转换为小写
 8         NSString* lowerStr = [str lowercaseString];
 9         NSLog(@"lowerStr = %@", lowerStr);
10         //转换成首字母大写
11         NSString* newStr = [str capitalizedString];
12         NSLog(@"newStr = %@", newStr);
13         
14         //字符串提取
15         //指定位置到结尾：
16         NSString* subStr = [str substringFromIndex:7];
17         NSLog(@"subStr = %@", subStr);
18         //从指定位置提取指定长度(通过 NSRange)
19         subStr = [str substringWithRange: NSMakeRange(7, 7)];
20          NSLog(@"subStr = %@", subStr);
21         //开头到指定位置
22         subStr = [str substringToIndex:6];
23          NSLog(@"subStr = %@", subStr);
24         
25         //字符串切割(componentsSeparatedByString:)方法
26         //此方法根据传递的字符串进行分割，并将分割的结果以数组返回
27         NSArray* strArr = [str componentsSeparatedByString:@" "];
28         for (id str in strArr) {
29             NSLog(@"%@", str);
30         }
31         //拼接数组中得字符串(按指定字符串)
32         NSString* myStr = [strArr componentsJoinedByString:@"__"];
33         NSLog(@"mystr = %@", myStr);
34         //根据传递进来的NSCharacterSet集合进行分割(示例中包含逗号“,”和空格“ ”)
35         strArr = [str componentsSeparatedByCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@", "]];
36         for (id str in strArr) {
37             NSLog(@"%@", str);
38         }

转载于:https://www.cnblogs.com/pretty-guy/p/3975088.html