NSString+NSMutableString+NSValue+NSAraay用法彙總

來源：CocoaChina

開發過程中難免遇到字符串操作，下面是CocoaChina爲您總結的NSString+NSMutableString+NSValue+NSAraay用法彙總，幫您應對各種字符串操作。

//一、NSString    
    /*----------------創建字符串的方法----------------*/

    //1、創建常量字符串。
    NSString *astring = @"This is a String!";


    //2、創建空字符串，給予賦值。

    NSString *astring = [[NSString alloc] init];
    astring = @"This is a String!";
    NSLog(@"astring:%@",astring);
  [astring release];




    //3、在以上方法中，提升速度:initWithString方法

    NSString *astring = [[NSString alloc] initWithString:@"This is a String!"];
    NSLog(@"astring:%@",astring);
    [astring release];



    //4、用標準c創建字符串:initWithCString方法

    char *Cstring = "This is a String!";
    NSString *astring = [[NSString alloc] initWithCString:Cstring];
    NSLog(@"astring:%@",astring);
    [astring release];



    //5、創建格式化字符串:佔位符（由一個%加一個字符組成）

    int i = 1;
    int j = 2;
    NSString *astring = [[NSString alloc] initWithString:[NSString stringWithFormat:@"%d.This is %i string!",i,j]];
    NSLog(@"astring:%@",astring);
    [astring release];



    //6、創建臨時字符串

    NSString *astring;
    astring = [NSString stringWithCString:"This is a temporary string"];
    NSLog(@"astring:%@",astring);




    /*----------------從文件讀取字符串:initWithContentsOfFile方法 ----------------*/    

    NSString *path = @"astring.text";
    NSString *astring = [[NSString alloc] initWithContentsOfFile:path];
    NSLog(@"astring:%@",astring);
    [astring release];


    /*----------------寫字符串到文件:writeToFile方法 ----------------*/    


    NSString *astring = [[NSString alloc] initWithString:@"This is a String!"];
    NSLog(@"astring:%@",astring);
    NSString *path = @"astring.text";    
    [astring writeToFile: path atomically: YES];
    [astring release];    




    /*---------------- 比較兩個字符串----------------*/        

    //用C比較:strcmp函數

    char string1[] = "string!";
    char string2[] = "string!";
    if(strcmp(string1, string2) = = 0)
    {
        NSLog(@"1");
    }



    //isEqualToString方法    
    NSString *astring01 = @"This is a String!";
    NSString *astring02 = @"This is a String!";
    BOOL result = [astring01 isEqualToString:astring02];
    NSLog(@"result:%d",result);




    //compare方法(comparer返回的三種值)    
    NSString *astring01 = @"This is a String!";
    NSString *astring02 = @"This is a String!";    
    BOOL result = [astring01 compare:astring02] = = NSOrderedSame;    
    NSLog(@"result:%d",result);    
    //NSOrderedSame 判斷兩者內容是否相同




    NSString *astring01 = @"This is a String!";
    NSString *astring02 = @"this is a String!";
    BOOL result = [astring01 compare:astring02] = = NSOrderedAscending;    
    NSLog(@"result:%d",result);
    //NSOrderedAscending 判斷兩對象值的大小(按字母順序進行比較，astring02大於astring01爲真)



    NSString *astring01 = @"this is a String!";
    NSString *astring02 = @"This is a String!";
    BOOL result = [astring01 compare:astring02] = = NSOrderedDescending;    
    NSLog(@"result:%d",result);     
    //NSOrderedDescending 判斷兩對象值的大小(按字母順序進行比較，astring02小於astring01爲真)



    //不考慮大 小寫比較字符串1
    NSString *astring01 = @"this is a String!";
    NSString *astring02 = @"This is a String!";
    BOOL result = [astring01 caseInsensitiveCompare:astring02] = = NSOrderedSame;    
    NSLog(@"result:%d",result);     
    //NSOrderedDescending判斷兩對象值的大小(按字母順序進行比較，astring02小於astring01爲 真)



    //不考慮大小寫比較字符串2
    NSString *astring01 = @"this is a String!";
    NSString *astring02 = @"This is a String!";
    BOOL result = [astring01 compare:astring02
                            options:NSCaseInsensitiveSearch | NSNumericSearch] = = NSOrderedSame;    
    NSLog(@"result:%d",result);     

    //NSCaseInsensitiveSearch:不區分大小寫比較 NSLiteralSearch:進行完全比較，區分大小寫 NSNumericSearch:比較字符串的字符個數，而不是字符值。


    /*----------------改變字符串的大小寫----------------*/    

    NSString *string1 = @"A String"; 
    NSString *string2 = @"String"; 
    NSLog(@"string1:%@",[string1 uppercaseString]);//大寫
    NSLog(@"string2:%@",[string2 lowercaseString]);//小寫
    NSLog(@"string2:%@",[string2 capitalizedString]);//首字母大小


    /*----------------在串中搜索子串 ----------------*/        

    NSString *string1 = @"This is a string";
    NSString *string2 = @"string";
    NSRange range = [string1 rangeOfString:string2];
    int location = range.location;
    int leight = range.length;
    NSString *astring = [[NSString alloc] initWithString:[NSString stringWithFormat:@"Location:%i,Leight:%i",location,leight]];
    NSLog(@"astring:%@",astring);
    [astring release];


    /*----------------抽取子串 ----------------*/        

    //-substringToIndex: 從字符串的開頭一直截取到指定的位置，但不包括該位置的字符
    NSString *string1 = @"This is a string";
    NSString *string2 = [string1 substringToIndex:3];
    NSLog(@"string2:%@",string2);




    //-substringFromIndex: 以指定位置開始（包括指定位置的字符），幷包括之後的全部字符
    NSString *string1 = @"This is a string";
    NSString *string2 = [string1 substringFromIndex:3];
    NSLog(@"string2:%@",string2);




    //-substringWithRange: //按照所給出的位置，長度，任意地從字符串中截取子串
    NSString *string1 = @"This is a string";
    NSString *string2 = [string1 substringWithRange:NSMakeRange(0, 4)];
    NSLog(@"string2:%@",string2);