串聯NSString的不行

Question

我試圖用

NSString* result = @""; 

for(NSString* test in self.selectedOnes) { 

    NSLog(test) ; 
    [result stringByAppendingString:test]; 
    [result stringByAppendingString:@","]; 
} 

但result來連接的NSMutableArray的內容保持@""，我敢肯定，selectedOnes包含數據，因爲它寫入日誌。

有什麼建議嗎？

Answer 1

stringByAppendingString:返回一個新的String。

這應該工作。

NSString* result = @""; 

for(NSString* test in self.SelectedOnes ) 
{ 
    NSLog(test) ; 
    result = [result stringByAppendingString:test]; 
    result = [result stringByAppendingString:@","]; 
} 

Answer 2

stringByAppendingString:返回一個新字符串

使用方法如下：

NSString* result = @""; 

for(NSString* test in self.SelectedOnes ) 
{ 
    NSLog(test) ; 



    result = [result stringByAppendingString:test]; 
    result = [result stringByAppendingString:@","]; 


} 

Answer 3

可以使用componentsJoinedByString方法，「構造並返回一個NSString對象，它是介於之間的給定分離的結果陣列」的元素，

NSString *result = [self.SelectedOnes componentsJoinedByString:@","]; 

Answer 4

嘗試這種方式

result = test; 
result = [result stringByAppendingString:@","];