在Java中检查空字符串 [英] Checking empty string in Java

问题描述

我不知道下面的代码有什么问题....我从文本框中获取输入并将输入放在一个字符串中。如果文本框为空，则返回空字符串。在下面的代码中

I don't know what is wrong with the below code.... I am getting input from a textbox and putting the input in a string. If the textbox is empty it will return a empty string. In the below code

   String[] str = new String[9]; 
   for(int i=0;i<9;i++){
       if(str[i].equals("")){
          System.out.println("set " + cmds[i] + " " + str[i]);
          WriteThread.sendCommand("set " + cmds[i] + " " + str[i] + "\n", false);
       }
    }

在上面的代码中 str [i] 存储文本框的输入文本，我试图检查数组的任何元素是否为空。我也试过 str [i] ==和 str [i] == null 但没有运气。 if块中的语句，如果我打印字符串 str [i] ，它显示没有任何意味着它是空的。

In the above code str[i] stores the input text of textboxes and I am trying to check if any element of the array is empty. I also tried with str[i] == "" and str[i] == null but no luck. The statement inside the if block if i am printing the string str[i], it shows nothing that means it is empty.

我做错了什么？

推荐答案

你可以尝试：

if (str[i] == null || str[i].trim().equals("")){
// your code
}

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