(ios) NSString (六)【子字串的相關處理】

【環境：xCode4.2 , ios5.1】
1.說明：From:從指定位置到結尾。To:從開頭到指定位置。WithRange:傳回一個範圍和NSRange並用

 
- (NSString *)substringFromIndex:(NSUInteger)from;
- (NSString *)substringToIndex:(NSUInteger)to;
- (NSString *)substringWithRange:(NSRange)range;//Hint: Use with rangeOfComposedCharacterSequencesForRange: to avoid breaking up composed characters

<以下範例>

 
    NSString *string1 = @"this blog is n11 studio";
    NSString *string2 = [string1 substringFromIndex:13];
    NSLog(@"%@",string2);
    //the answer is "n11 studio" 

2.說明：Pre:判斷接收訊息的物件開頭是否為aString。Suf:判斷結尾是否是aString

- (BOOL)hasPrefix:(NSString *)aString;
- (BOOL)hasSuffix:(NSString *)aString;