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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：

NSNumber::比較大小

NSNumber compare

!!! 切記！儲存於NSNumber物件的值，擷取時必須要一致。
擷取時輸出型態與儲存時的型態不同時，系統並不會出錯，而會輸出無效的值

        NSNumber        *myNumber, *floatNumber, *intNumber;
        NSInteger       myInt;
        NSComparisonResult compareResult1, compareResult2;

        intNumber = [NSNumber numberWithInteger: 100];
        floatNumber = [NSNumber numberWithFloat: 100.00];
        myNumber = [NSNumber numberWithDouble: 123456e+15];
        
        compareResult1 = [intNumber compare: myNumber];
        compareResult2 = [intNumber compare: floatNumber];
        //NSOrderedAscending    <  官方解釋(The left operand is smaller than the right operand.)
        //NSOrderedSame        ==  官方解釋(The two operands are equal.)
        //NSOrderedDescending   >  官方解釋(The left operand is greater than the right operand.)
        if(compareResult1 == NSOrderedAscending)
            NSLog(@"intNumber is less than myNumber");
        else if(compareResult1 == NSOrderedSame)
            NSLog(@"intNumber is equal to myNumber");
        else if(compareResult1 == NSOrderedDescending)
            NSLog(@"intNumber is greater than myNumber");
        else
            NSLog(@"What the fuck?!");

        if(compareResult1 == NSOrderedAscending)
            NSLog(@"intNumber is less than floatNumber");
        else if(compareResult1 == NSOrderedSame)
            NSLog(@"intNumber is equal to floatNumber");
        else if(compareResult1 == NSOrderedDescending)
            NSLog(@"intNumber is greater than floatNumber");
        else
            NSLog(@"What the fuck?!");

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;
}