为什么此javascript无法在页面加载时运行，而仅在刷新时运行？

Question

<!DOCTYPE html>
<html>
<head>
</head>
<body>
<script type = "text/javascript">
    function problem(){
        var num1 = parseInt(Math.random()*11);
        var num2 = parseInt(Math.random()*11);  
        document.write("What is " + num1 + " + " + num2);
        var answer = num1 + num2;
        //document.write(answer);
        ans = prompt("Enter your answer??");
        if(ans == answer){
            alert("Good JOB!");
        }else{
            alert("Fail xD");
        }
    }
    problem();
</script>
</body>
</html>

So, when I run this the prompt window doesn't pop up automatically, it comes up when it refresh, I want to appear right when i run the program. 因此，当我运行此程序时，提示窗口不会自动弹出，而是在刷新时弹出，我希望在运行程序时显示正确。

Answer 1

Don't use document.write as it will overwrite the page's content. 不要使用document.write，因为它将覆盖页面的内容。 Instead, create an element to hold the question (like a div) and refer to it like: 相反，创建一个元素来保存问题（例如div），并像这样引用它：

function problem() {
    var num1 = parseInt(Math.random() * 11);
    var num2 = parseInt(Math.random() * 11);
    document.getElementById('foo').innerHTML = "What is " + num1 + " + " + num2;
    var answer = num1 + num2;
    ans = prompt("Enter your answer??");
    if (ans == answer) {
        alert("Good JOB!");
    } else {
        alert("Fail xD");
    }
}
problem();

jsFiddle example jsFiddle示例

为什么此javascript无法在页面加载时运行，而仅在刷新时运行？

问题描述

1 个解决方案

解决方案1
2 2014-02-20 22:32:55

为什么此javascript无法在页面加载时运行，而仅在刷新时运行？

问题描述

1 个解决方案

解决方案1 2 2014-02-20 22:32:55

解决方案1
2 2014-02-20 22:32:55