我正在尝试创建一个程序，我要求用户输入两个数字输入，然后在添加到一起时显示这两个数字的值（显示类似1 + 2 = 3），然后显示这两个数字相乘（1 * 2 = 2）。示例输出应如下所示，但基于从网站用户收到的输入：
1 + 2 = 3
1 * 2 = 2
像这样使用prompt：
var number1 = parseInt(prompt("Enter a number"));
var number2 = parseInt(prompt("Enter another number"));
document.write(`${number1} + ${number2} = ${number1 + number2}<br>${number1} * ${number2} = ${number1 * number2}`);您可以使用输入标记来获取输入，使用.innerHTML输出到html
function a() {
document.getElementById("c").innerHTML = Number(document.getElementById("a").value) + Number(document.getElementById("b").value);
}<input type="number" id="a" />
<input type="number" id="b" onkeyup="a()" />
<div id="c"></div>试试这个
function submit() {
let test =document.getElementById("text");
let sum = parseFloat(document.getElementById("firstNumber").value) +parseFloat(document.getElementById("lastNumber").value);
let mul = parseFloat(document.getElementById("firstNumber").value) * parseFloat(document.getElementById("lastNumber").value);
test.innerHTML = document.getElementById("firstNumber").value + ' + ' +document.getElementById("lastNumber").value + " = " +sum +" </br>";
test.innerHTML += document.getElementById("firstNumber").value + ' * ' +document.getElementById("lastNumber").value + " = " + mul +"\n";
return true;
} First number:<br>
<input type="number" id="firstNumber" >
<br>
Last number:<br>
<input type="number" id="lastNumber" >
<br><br>
<button onclick="return submit();">click</button>
<div id="text"></div>这是您的编程水平可能更熟悉的另一种方法。在这种情况下，我们有输入字段而不是提示。
<!DOCTYPE html>
<html>
<head>
<script>
function calc(){
var num1 = document.getElementById("in1").value;
var num2 = document.getElementById("in2").value;
document.getElementsByTagName("p")[0].innerHTML = num1 + "+" + num2 + "=" + (parseInt(num1) + parseInt(num2));
}
</script>
</head>
<body>
<input id="in1" type="number"/>
<input id="in2" type="number"/>
<button onclick="calc()">Calculate</button>
<p></p>
</body>
</html>
因为没有说明我想假设，你在用户访问页面时要求输入数字，而我通过提示请求收到这些输入...
<script>
function init(){
var input1 = prompt("Please enter the first Number", "First Number");
var input2 = prompt("Please enter the second Number", "Second Number");
if (input1 != null && input2 != null) {
sum = parseInt(input1) + parseInt(input2);
str1 = input1 + " + " + input2 + " = " + sum;
multi = parseInt(input1) * parseInt(input2);
str2 = input1 + " * " + input2 + " = " + multi;
document.getElementById("message").innerHTML = str1 + "<br/>" + str2;
}else{
alert('...error message');
}
} //end of function...
</script>
<body onload="init()">
......
<div id="message"></div>
</body>
这应该工作，如预期的那样......