可变字符串

//

//  main.m

//  可变的字符串

//

//  Created by 博博 on 16/1/7.

//  Copyright (c) 2016年 com.bb. All rights reserved.

//

#define NSLog(FORMAT, ...) printf("%s ", [[NSString stringWithFormat:FORMAT, ##__VA_ARGS__] UTF8String])

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[]) {

    @autoreleasepool {

        //nsstring父类  可变字符串子类

        NSMutableString *mustr=[[NSMutableString alloc]init];

        NSMutableString *mustr1=[NSMutableString stringWithFormat:@"hello"];

        NSLog(@"str=%@",mustr1);

        NSString *str=@"welcome to oc";

        mustr=[NSMutableString stringWithString:str];

        NSLog(@"%@",mustr);

        

        //插入

        [mustr insertString:@" student" atIndex:7];

        NSLog(@"%@",mustr);

        [mustr appendString:@" teacher"];//插入末尾

        NSLog(@"%@",mustr);

        [mustr appendFormat:@"第二遍:%@",str];

        NSLog(@"%@",mustr);

        //删除

        [mustr deleteCharactersInRange:NSMakeRange(8, 9)];

        NSLog(@"%@",mustr);

        //查找并删除

        NSRange rang=[mustr rangeOfString:@"teacher第二遍:welcome to oc"];

        if(rang.location!=NSNotFound){

            [mustr deleteCharactersInRange:rang];

        }

        NSLog(@"%@",mustr);

        //重新赋值

        [mustr setString:str];

        NSLog(@"%@",mustr);

        //替换

        NSRange rang1=[mustr rangeOfString:@"oc"];

        [mustr replaceCharactersInRange:rang1 withString:@"ios"];

        NSLog(@"%@",mustr);

    }

    return 0;

}