在这段代码中，我想通过单击值按钮

Question

我想通过点击通过每个值按钮通过以下函数添加值增加值

function sum() { 
 
    var txtFirstNumberValue = document.getElementById('txt1').value; 
 
    var txtSecondNumberValue = document.getElementById('txt2').value; 
 
    var txtThirdNumberValue = document.getElementById('txt3').value; 
 
    var txtFourthNumberValue = document.getElementById('txt4').value; 
 
    var result = parseInt(txtFirstNumberValue) + parseInt(txtSecondNumberValue); 
 
    var result = parseInt(txtFirstNumberValue) + parseInt(txtThirdNumberValue); 
 
    var result = parseInt(txtFirstNumberValue) + parseInt(txtFourthNumberValue); 
 
    if (!isNaN(result)) { 
 
    document.getElementById('txt1').value = result; 
 
    } 
 
} 
 
// Here I gave the other two events to add to the text field by the id names

<!-- here I gave the three Value buttons and on click function --> 
 
<input type="text" id="txt1" value="10" /> 
 
<input type="button" id="txt2" value="10" onClick="sum();" /> 
 
<input type="button" id="txt3" value="20" onClick="sum();" /> 
 
<input type="button" id="txt4" value="30" onClick="sum();" />

Answer 1

你可以通过将this.value传递给onClick函数获取按钮的值，其中this表示元素本身。

function sum(value) { 
 
    document.getElementById('txt1').value = Number(document.getElementById('txt1').value) + Number(value); 
 
}

<input type="text" id="txt1" value="10" /> 
 
<input type="button" id="txt2" value="10" onClick="sum(this.value);" /> 
 
<input type="button" id="txt3" value="20" onClick="sum(this.value);" /> 
 
<input type="button" id="txt4" value="30" onClick="sum(this.value);" />

Answer 2

这个JavaScript会帮助你。

<script> 
    function sum(e) { 
     var result = parseInt(e.value) + parseInt(document.getElementById('txt1').value); 
     if (!isNaN(result)) { 
       document.getElementById('txt1').value = result; 
      } 
    } 
</script>