Javascript计算保存变量 [英] Javascript calculations holding variables

问题描述

我在javascript中运动，我已经制作了这个脚本，以便计算2个变量的总和，然后在第三个等式中使用这个总和！任何关于如何使这项工作的想法都非常有用！

I'm exercising in javascript and i've made this script in order to calculate the sum of 2 variables and then use this sum in a third equation! any thoughts on how to make this work will be very useful!

<form name="Calcultor" Method="Get" id='form1'>First Number:
    <input type="text" name="fnum" size="35" id="first">+ Second Number:
    <input type="text" name="snum" size="35" id="sec">
    <br>
    <br>Answer:
    <input type="text" name="ans" size="35" id="ans" />
    <input type="text" name="ans2" size="35" id="ans2" />
    <button type="button" onclick="Calculate();">Calculate</button>
</form>
<script lang="javascript">
    function Calculate() {
        var first = document.getElementById('first').value;
        var sec = document.getElementById('sec').value;
	var ans = document.getElementById('ans').value;

        document.getElementById('ans').value = parseInt(first) + parseInt(sec);
	document.getElementById('ans2').value = parseInt(ans);
        document.form1.submit();
    }
</script>

提前致谢！

推荐答案

这是：

function Calculate() {
    var first = document.getElementById('first').value;
    var sec = document.getElementById('sec').value;
    var ans = document.getElementById('ans').value;

    document.getElementById('ans').value = parseInt(first) + parseInt(sec);
    document.getElementById('ans2').value = document.getElementById('ans').value;
    /*document.form1.submit();*/
}

<form name="Calcultor" Method="Get" id='form1'>First Number:
    <input type="text" name="fnum" size="35" id="first">+ Second Number:
    <input type="text" name="snum" size="35" id="sec">
    <br>
    <br>Answer:
    <input type="text" name="ans" size="35" id="ans" />
    <input type="text" name="ans2" size="35" id="ans2" />
    <button type="button" onclick="Calculate();">Calculate</button>
</form>

如果有什么不清楚，请随时询问！

Feel free to ask, if anything isn't clear!

更新（增加最后输入价值乘以）：

function Calculate() {
    var first = document.getElementById('first').value;
    var sec = document.getElementById('sec').value;
    var ans = document.getElementById('ans').value;

    document.getElementById('ans').value = parseInt(first) + parseInt(sec);
    document.getElementById('ans2').value = parseInt(document.getElementById('ans').value) + 1;
    /*document.form1.submit();*/
}

<form name="Calcultor" Method="Get" id='form1'>First Number:
    <input type="text" name="fnum" size="35" id="first">+ Second Number:
    <input type="text" name="snum" size="35" id="sec">
    <br>
    <br>Answer:
    <input type="text" name="ans" size="35" id="ans" />
    <input type="text" name="ans2" size="35" id="ans2" />
    <button type="button" onclick="Calculate();">Calculate</button>
</form>

在对数字求和之前，你应该使用 parseInt（），而没有解析的值你总结字符串，带数字，并且正如预期的那样，结果将是一个包含多个字符的字符串。

You should use parseInt() before summing numbers, without parsed value you are summing string with number, and as expected, the result will be a string with one more character.

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