字元串常用方法

字元串大小寫方法

-(NSString *)uppercaseString:将字元全改成大寫的;

  -(NSString *)lowercaseString:将字元全改成小寫的;

  -(NSString *)capitalcaseString:将首個字元改成大寫,其餘的都小寫;
           

字元串的替換函數

-(NSString *)stringByReplacingOccurrencesOfString:(NSString *)targetwithString:(NSString *)replacement:将原字元串中的所有的target替換成replacement

  -(NSString *)stringByReplaceingCharactersInRange:(NSRange)withString:(NSRange)rangewithString:(NSString *)replacement:将原字元串中range範圍内的内容替換成replacement;

  -(NSArray *)componentsSeparatedByString:(NSString *)separator:以separator:以separator為分隔符,将原字元串中的内容進行分割,分割得到的結果放到一個數組裡,作為傳回值
           

可變字元串

初始化方法

NSMutableString *mString = [NSMutableString stringWithString:@"nihao"];

    NSMutableString *mString1 = [NSMutableString stringWithFormat:@"hello"];
    NSMutableString *mString2 = [NSMutableString stringWithContentsOfFile:@"" encoding:4 error:nil];
    NSMutableString *mString3 = [NSMutableString stringWithContentsOfURL:[NSURL URLWithString:@""] encoding:4 error:nil];
    //可變字元串獨特初始化方式，初始化一個空間為100的空的可變字元串
    NSMutableString *mString4 = [[NSMutableString alloc] initWithCapacity:100];
           

2.操作(不可變字元串的API)

C 語言字元數組轉換成 OC的字元串

NSString *targetString = @"你麻痹";

    NSMutableString *targetString = [NSMutableString stringWithString:@"你麻痹"];

    NSRange range = [targetString rangeOfString:@"麻痹"];

    [targetString replaceCharactersInRange:range withString:@"**"];

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

增加

在指定位置去插入一段字元串

    [targetString insertString:@",你是sb麼，有點意識，OK？"   

    atIndex:targetString.length];

    NSLog(@"targetString = %@",targetString);
    在字元串的末尾添加一個字元串

    [targetString appendString:@"不想玩，滾！"];

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

    在字元串的末尾添加多個字元串

    [targetString appendFormat:@"%@%@",@"fuck!",@"your mom boom boom boom"];

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

替換

range = [targetString rangeOfString:@"sb"];

    [targetString replaceCharactersInRange:range withString:@"**"];

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

删除

[targetString deleteCharactersInRange:NSMakeRange(0, 3)];

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

NSArray/NSMutableArray

在OC中,我們用

NSArray

類和

NSMutableArray

類來表示數組.其中

NSArray

類是

NSMutableArray

類的父類.在oc中,我們的數組是有序的

對象

的集合,

即我們的數組隻能存儲’對象’.在OC中我們的數組中元素類型不能是

int

,

float

,

CGPoint

等類型.

NSArray

1初始化方法

//川建一個空的不可變的數組
    NSArray *array1=[[NSArray alloc]init];
    NSArray *array2=[NSArray array];
    //建立一個裡面隻有一個元素的不可變數組
    NSArray *array3=[NSArray arrayWithObject:@"zhoudu"];
    //建立一個裡面有多個元素的不可變數組
    NSArray *array4=[NSArray arrayWithObjects:@"linfurong",@"xingzhenyu",@"zhuweijian",@"keyi", nil];
    NSLog(@"Hello, World!");
    //新文法
    NSArray *array5=@[@"zhoudu"];
    NSArray *array6=@[@"linfurong",@"zhuweijian",@"keyi"];
    //
   // NSArray *array7=[NSArray arrayWithArray:@""];