字符串

1.编写一个程序，使用NSString和NSMutableString实例化一些NSString类的对象，然后比较其是否相等，大小。实例化一个NSMutableString的对象，然后将之前的NSString对象加入其中，然后再删除几个，要求使用NSRange结构体

#import <Foundation/Foundation.h>

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

{

    @autoreleasepool

    {

        // NSString

        NSString *str1=@"hello word!";

        NSString *str2=@"Hello Word!";

        // isEqualToString  区分大小写的

        // 判断是否相等

        if ([str1 isEqualToString:str2]==YES)

        {

            NSLog(@"相等");

        }

        else

        {

            NSLog(@"不相等");

 

        }

        

        //区分大小写的比较大小

        

        if ([str1 compare:str2]==NSOrderedAscending)

        {

            NSLog(@"str1>str2");

        }

        else if([str1 compare:str2]==NSOrderedSame)

        {

            NSLog(@"str1=str2");

        }

        else

        {

            NSLog(@"str1<str2");

        }

        

        // 不区分大小写的比较大小

        if ([str1 compare:str2 options:NSCaseInsensitiveSearch]==-1)

        {

            NSLog(@"str1<str2");

        }

        else if ([str1 compare:str2 options:NSCaseInsensitiveSearch]==0)

        {

            NSLog(@"str1=str2");

        }

        else

        {

            NSLog(@"str1>str2");

        }

        

        // NSMutableAttributedString

        NSMutableString *str3=[NSMutableString stringWithCapacity: 100];

        [str3 appendFormat:@"hello word!"];

        [str3 appendFormat:@"Hello Word!"];

        [str3 appendString:@"my name isxyl"];

        [str3 appendString:@"age is 24"];

        

        [str3 insertString:@"addess is guiyang" atIndex:20];

        

        NSRange range1=[str3 rangeOfString:@"addess is guiyang"];

        NSRange range2=[str3 rangeOfString:@"hello word!"];

        [str3 deleteCharactersInRange:range1];

        [str3 deleteCharactersInRange:range2];

        

        NSLog(@"%@",str3);

        NSLog(@"%ld",[str3 length]);

    }

    return 0;

}

2.编写程序，将”Hello World and Sunshine.”字符串中的”World”替换为”lamco”，  并将替换前和替换后的字符串输出 本题要求做两次，使用NSString两种替换方法完

方法一：

#import <Foundation/Foundation.h>

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

{

    @autoreleasepool

    {

        NSString *str1=@"hello World and Sunshine";

        NSLog(@"替换前:%@",str1);

        NSString*str2=[str1 stringByReplacingOccurrencesOfString:@"World" withString:@"lamco"];

        NSLog(@"替换后:%@",str2);

    }

    return 0;

}

方法二：

#import <Foundation/Foundation.h>

 

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

{

    @autoreleasepool

    {

        NSMutableString *str1=[NSMutableString stringWithCapacity:100];

        [str1 appendString:@"hello World and Sunshine"];

        NSLog(@"替换前:%@",str1);

        // 要注意替换的字符串

        NSRange range1=[str1 rangeOfString:@"World"];

        [str1 replaceCharactersInRange:range1 withString:@"lamco"];

        NSLog(@"替换后:%@",str1);

        NSLog(@"%ld",[str1 length]);

        

    }

    return 0;

}