字符串的替换（直接替换你想要替换的字符串内容）／删除（删除指定位置／删除你要要删除的位置）／

#import <Foundation/Foundation.h>

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

@autoreleasepool {

NSMutableString *mustr1=[[NSMutableString alloc]init];

NSMutableString *mustr2=[NSMutableString stringWithFormat:@"Hello"];

NSMutableString *mustr3=[[NSMutableString alloc]init];

NSString *[email protected]"welcom to OC";

//NSMutableString *[email protected]"welcom to OC";     这是错误的——不可以将字符串常量直接赋值给NSMutableString

//赋值

mustr1=[NSMutableString stringWithString:str];

NSLog(@"mustr1=%@",mustr1);

//替换字符串

NSRange rang2=[mustr1 rangeOfString:@"OC"];

[mustr1 replaceCharactersInRange:rang2 withString:@"IOS"];

NSLog(@"mustr1=%@",mustr1);

//插入

[mustr1 insertString:@" student" atIndex:6];        //指定位置6插入字符串

[mustr2 appendString:@" teacher!"];                  //末尾插入字符串

[mustr3 appendFormat:@"Hey!%@",str];                //格式化插入字符串

NSLog(@"mustr1=%@",mustr1);

NSLog(@"mustr2=%@",mustr2);

NSLog(@"mustr3=%@",mustr3);

//指定位置删除

[mustr1 deleteCharactersInRange:NSMakeRange(7, 8)];     //在位置7删除8个字符

NSLog(@"mustr1=%@",mustr1);

//查找删除

NSRange rang1=[mustr2 rangeOfString:@"teacher"];

if(rang1.location!=NSNotFound) {

[mustr2 deleteCharactersInRange:rang1];

}

NSLog(@"mustr2=%@",mustr2);

//重新赋值

[mustr2 setString:str];

NSLog(@"mustr2=%@",mustr2);

}

return 0;

}