foundation 框架 NSString常用总结(二)

以此作为NSString常用总结（一）的补充

 　　　　　NSString* str = [NSString stringWithFormat:@"I love programing! You, come here"];

         //字符串对象的大小写转换

         //转换为大写

         NSString* upStr = [str uppercaseString];

         NSLog(@"str = %@", str);

         NSLog(@"upStr = %@", upStr);

         //转换为小写

         NSString* lowerStr = [str lowercaseString];

         NSLog(@"lowerStr = %@", lowerStr);

         //转换成首字母大写

         NSString* newStr = [str capitalizedString];

         NSLog(@"newStr = %@", newStr);

         //字符串提取

         //指定位置到结尾：

         NSString* subStr = [str substringFromIndex:];

         NSLog(@"subStr = %@", subStr);

         //从指定位置提取指定长度(通过 NSRange)

         subStr = [str substringWithRange: NSMakeRange(, )];

          NSLog(@"subStr = %@", subStr);

         //开头到指定位置

         subStr = [str substringToIndex:];

          NSLog(@"subStr = %@", subStr);

         //字符串切割(componentsSeparatedByString:)方法

         //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

         NSArray* strArr = [str componentsSeparatedByString:@" "];

         for (id str in strArr) {

             NSLog(@"%@", str);

         }

         //拼接数组中得字符串(按指定字符串)

         NSString* myStr = [strArr componentsJoinedByString:@"__"];

         NSLog(@"mystr = %@", myStr);

         //根据传递进来的NSCharacterSet集合进行分割(示例中包含逗号“,”和空格“ ”)

         strArr = [str componentsSeparatedByCharactersInSet:[NSCharacterSet characterSetWithCharactersInString:@", "]];

         for (id str in strArr) {

             NSLog(@"%@", str);

         }