OC-->NSMutableString常用方法

#import <Foundation/Foundation.h>

int main(int argc, const char * argv[])
{
    @autoreleasepool
    {
        //可变字符串是字符串的子类
        NSMutableString *str = [[NSMutableString alloc] initWithCapacity:1];
        [str setString:@"Hello"];
        
        //1.追加字符串
        [str appendString:@" World"];
        NSLog(@"str = %@", str);
        int a = 100;
        [str appendFormat:@" a = %d", a];
        NSLog(@"str = %@", str);
        
        //2.替换字符串
        NSRange rang = [str rangeOfString:@"World"];
        [str replaceCharactersInRange:rang withString:@"IOS"];
        NSLog(@"str = %@", str);
        
        //3.插入字符串
        [str insertString:@"AAA" atIndex:6];
        NSLog(@"str = %@", str);
        
        //4.删除字符串
        NSRange rang1 = [str rangeOfString:@"AIOS"];
        [str deleteCharactersInRange:rang1];
        NSLog(@"str = %@", str);
    }
    return 0;
}

2016-08-10 14:58:17.314 NSMutableString[1215:182470] str = Hello World
2016-08-10 14:58:17.315 NSMutableString[1215:182470] str = Hello World a = 100
2016-08-10 14:58:17.315 NSMutableString[1215:182470] str = Hello IOS a = 100
2016-08-10 14:58:17.315 NSMutableString[1215:182470] str = Hello AAAIOS a = 100
2016-08-10 14:58:17.316 NSMutableString[1215:182470] str = Hello AA a = 100
Program ended with exit code: 0