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NSMutableString replace 字串置換

NSMutableString replace 字串置換方法

!!!Range定義
 typedef struct _NSRange {
    NSUInteger location;
    NSUInteger length;
} NSRange;
location其實就是index
length表示從index開始幾個字元
...

    NSMutableString *myMSstr1;
    NSMutableString *myMSstr2;
    myMSstr1 = [NSMutableString stringWithFormat: @"Please don't see."];
    // replace a range of chars with another (replace:置換)(將Range範圍內的字元替換)
    [myMSstr1 replaceCharactersInRange: NSMakeRange(7, 10)
                        withString: @"see me."];
    NSLog(@"%@", myMSstr1);
        
    myMSstr2 = [NSMutableString stringWithFormat: @"%@%@%@%@%@", myMSstr1, myMSstr1, myMSstr1, myMSstr1, myMSstr1];
        
    NSString            *search, *replace;
    NSRange RangeOfStr;
    // Search and replace
    search = @"see me.";
    replace = @"don't see.";
    RangeOfStr = [myMSstr1 rangeOfString: search];
    if(RangeOfStr.location != NSNotFound){
        [myMSstr1 replaceCharactersInRange: RangeOfStr withString: replace];
        NSLog(@"%@", myMSstr1);
    }
    // Search and replace All  搜尋所有search字串置換為replace字串
    RangeOfStr = [myMSstr2 rangeOfString: search];
    while(RangeOfStr.location != NSNotFound){
        [myMSstr2 replaceCharactersInRange: RangeOfStr withString: replace];
        NSLog(@"%@", myMSstr2);
        RangeOfStr = [myMSstr2 rangeOfString: search];
    }
執行結果：

NSString::取得字串長度(Get NSString Length)  

NSString *str1 = @"This is string A";
NSLog(@"Length of str1: %lu", [str1 length]);

執行結果：

Objective Static

…

靜態變數預設的初始值為0，且執行期間只會被初始一次，以下使用Static關鍵字實現方法呼叫次數

@interface Page: NSObject
-(void) showTimes;
@end

@implementation Page
-(void) showTimes
{
    static int PageTimes;
    ++PageTimes;
    NSLog(@"showTimes Call Times : %i", PageTimes);
}
@end

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        
        Page *myPage = [Page new];
        [myPage showTimes];
        
        Page *myPage2 = [Page new];
        [myPage2 showTimes];
        
        Page *myPage3 = [Page new];
        [myPage3 showTimes];
        
    }
    return 0;
}