//

//  main.m

//  NSString

/**

    NSString

    1.NSString 是一个不可以变的字符串对象

    2.NSMutableString是一个可变字符串。

 　　下面代码为字符串的：增、删、替换、查方法得演示。

 */

#import <Foundation/Foundation.h>

void MutableNSString(){

    NSMutableString *mutableString  =[NSMutableString stringWithFormat:@"我是可变字符串"];

    //指定位置增加字符串

    [mutableString insertString:@"增加" atIndex:([mutableString length])];

    NSLog(@"%@",mutableString);

    //指定范围替换全部字符串

    [mutableString replaceCharactersInRange:NSMakeRange(, [mutableString length]) withString:@"替换后得字符串"];

    NSLog(@"%@",mutableString);

    NSRange rang  = [mutableString rangeOfString:@"字符串"];

    [mutableString replaceCharactersInRange:rang withString:@"string"];

    NSLog(@"%@",mutableString);

    //重新设置可变字符串内容

    [mutableString setString:@"ABCDAa"];

    //将A替换成E，方式为区分大小

    [mutableString replaceOccurrencesOfString:@"A" withString:@"E" options:NSLiteralSearch range:NSMakeRange(, [mutableString length])];

    NSLog(@"%@",mutableString);

    //删除指定范围得字符串

    NSRange deleteRang =  [mutableString rangeOfString:@"a"];

    //删除前最好判断是否存在,或者使用@try捕捉异常

    [mutableString deleteCharactersInRange:deleteRang];

    NSLog(@"%@",mutableString);

}

void BaseStringMeth(){

    //字符串的基本方法

    NSString *str1  =  @"hello NSString ";

    //查询字符串得长度

    NSUInteger length=  [str1 length];

    NSLog(@"length = %lu",length);

    // 转换大写

    NSString *upperNSString = [str1 uppercaseString];

    NSLog(@"%@",upperNSString);

    //转换小写

    NSString *lowerNSString = [str1 lowercaseString];

    NSLog(@"%@",lowerNSString);

    //字符换链接

    NSString *appendString  = @"study ";

    NSString *afterAppendString = [appendString stringByAppendingString:str1];

    NSLog(@"%@",afterAppendString);

    //判断字符串是否相等

    NSString *a = @"string a";

    NSString *b = @"string b";

    NSString *c = @"string a";

    NSString *d = @"String a";

    NSString *e = @"Strina a";

    if([a isEqualToString:b] != YES){

        NSLog(@"不相等");

    }

    if([a isEqualToString:c]){

        NSLog(@"相等");

    }

    // 这个判断是严格区分大小写

    if([a isEqualToString:d]){

        NSLog(@"相等");

    }

    //字符串比较大小，字符串得比较其实就是比较

    NSString *compare1= @"";

    NSString *compare2 = @"";

    //- (NSComparisonResult)compare:(NSString *)string; 比较方法返回值是NSComparisonResult,他是一个枚举类型

    //typedef NS_ENUM(NSInteger, NSComparisonResult) {NSOrderedAscending = -1L, NSOrderedSame, NSOrderedDescending};

    if([compare1 compare:compare2] == NSOrderedAscending ){

        NSLog(@"compare1 <compare2");

    }else if ([compare1 compare:compare2] == NSOrderedSame ){

        NSLog(@"compare1 ==compare2");

    }else if ([compare1 compare:compare2] == NSOrderedDescending){

        NSLog(@"compare1 >compare2");

    }

    NSString *compare3= @"res1";

    NSString *compare4 = @"RES1";

    if([compare3 compare:compare4] == NSOrderedAscending ){

        NSLog(@"compare3 <compare4");

    }else if ([compare3 compare:compare4] == NSOrderedSame ){

        NSLog(@"compare3 ==compare4");

    }else if ([compare3 compare:compare4] == NSOrderedDescending){

        NSLog(@"compare3 >compare4");

    }

    //忽略大小写的比较

    if([compare3 caseInsensitiveCompare:compare4] == NSOrderedAscending ){

        NSLog(@"compare3 <compare4");

    }else if ([compare3 caseInsensitiveCompare:compare4] == NSOrderedSame ){

        NSLog(@"compare3 ==compare4");

    }else if ([compare3 caseInsensitiveCompare:compare4] == NSOrderedDescending){

        NSLog(@"compare3 >compare4");

    }

}

void NSStringSearch(){

    //字符串的查找

    NSString *str1  =  @"hello NSString ";

    NSString *hello = @"hello";

    //查找hello字符串的位置

    NSRange helloRang = [str1 rangeOfString:hello];

    NSLog(@"hello location=%lu and length=%lu",helloRang.location,helloRang.length);

    NSString *hello2 = @"hello2";

    NSRange helloRang2 = [str1 rangeOfString:hello2];

    //找不到对应的字符串的时候系统会返回一个NSNotFound

    if(helloRang2.location  == NSNotFound){

        NSLog(@"在%@,中没有找到对应的字符串%@",str1,hello2);

    }

    /**

     传入 NSStringCompareOptions 枚举的值

     enum{

     NSCaseInsensitiveSearch = 1,//不区分大小写比较

     NSLiteralSearch = 2,//区分大小写比较

     NSBackwardsSearch = 4,//从字符串末尾开始搜索

     NSAnchoredSearch = 8,//搜索限制范围的字符串

     NSNumbericSearch = 64//按照字符串里的数字为依据，算出顺序。例如 Foo2.txt < Foo7.txt < Foo25.txt

     //以下定义高于 mac os 10.5 或者高于 iphone 2.0 可用

     NSDiacriticInsensitiveSearch = 128,//忽略 "-" 符号的比较

     NSWidthInsensitiveSearch = 256,//忽略字符串的长度，比较出结果

     NSForcedOrderingSearch = 512//忽略不区分大小写比较的选项，并强制返回 NSOrderedAscending 或者 NSOrderedDescending

     //以下定义高于 iphone 3.2 可用

     NSRegularExpressionSearch = 1024//只能应用于 rangeOfString:..., stringByReplacingOccurrencesOfString:...和 replaceOccurrencesOfString:... 方法。使用通用兼容的比较方法，如果设置此项，可以去掉 NSCaseInsensitiveSearch 和 NSAnchoredSearch

     }

     */

    //指定范围进行查找。我们可以通过options来确定查询得方式。从头开始还是从尾开始

    NSRange nsstringRang= [str1 rangeOfString:@"NSString" options:NSCaseInsensitiveSearch range:NSMakeRange(, [str1 length])];

    NSLog(@"location=%lu,length=%lu",nsstringRang.location,nsstringRang.length);

}

//字符串的截取

void SubString(){

    //字符串截取

    NSString *str1  =  @"hello NSString ";

    //从第5个字符开始截取到最后

    NSString *subString = [str1 substringFromIndex:];

    NSLog(@"%@",subString);//输出NSString

    NSRange rang = {,};

    //指定范围得截取

    NSString *subByRang = [str1 substringWithRange:rang];

    NSLog(@"%@",subByRang);//输出hello

    //从0开始截取到指定的位置

    NSString *subToPosition= [str1 substringToIndex:];

    NSLog(@"%@",subToPosition);//输出hello

}

//字符串的创建

void CreateNSString(){

    //字符串的创建

    NSString *str1 = @"hello NSString ";

    //静态方法创建字符串,

    NSString *str2 = [NSString stringWithFormat:@"NSString%i",];

    //动态创建字符串,由于动态创建计数器会+1因此我们需要自己释放，str3初始化时没有相应的值

    NSString *str3 = [[NSString alloc]init];

    NSLog(@"%@",str3);

    [str3 release];

}

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

    @autoreleasepool {

        CreateNSString();

        BaseStringMeth();

        SubString();

        NSStringSearch;

        MutableNSString();

    }

    return ;

}