如何在JavaScript中比较等于'=' [英] how to compare equals '=' in javascript

问题描述

我正在用JavaScript和HTML编写计算器程序.我有一个带有值"="的按钮.在那种情况下，当用户单击计算器中的"=" 按钮时.它应该开始评估他/她到目前为止提供的输入.但是当用户单击"="按钮时，我试图像这样

I am doing a calculator program in javascript and HTML. I have a button with a value '=' in it. In that one when a user click on "=" button in calculator. it should start evaluate the input he/she had given so far. But when a user click '=' button i tried to compare like this

$(".calcinput").click(function () {
        var res = $(this).val();
        if (res == '=') {
            //code to handle when '=' is pressed;
        }
   }

但是它没有用，请帮助我.

but it didn't work please help me.

推荐答案

您的代码good足以处理事件..只需在comapre中添加一个额外的=

Your code is good enough to handle the event .. Just add an extra = in comapre

$(".calcinput").click(function () {
    var res = $(this).val();
    //if (res == '=') {
      if (res === '=') {
        //code to handle when '=' is pressed;
    }
});

下一步检查使用div或button或其他元素表示button =

Next check where you used div or button or something else element to represent the button =

如果是button，请使用val()提取值

var res = $(this).val();

如果元素是div，则可能是innerHTML或innerTEXT

If the element is div then it could be innerHTML or innerTEXT

 var res = $(this).innerHTML;
 //Or
 var res = $(this).innerText;

您可以添加一条额外的行，以检查您是否获得了正确的element

You can add an extra line to check whether you getting proper value of element

var res = $(this).val();
alert(res);

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