javascript 如果数字大于数字 [英] javascript if number greater than number

问题描述

我有这个 javascript 函数来验证一个数字是否大于另一个数字

I have this javascript function to validate if a number is greater than another number

function validateForm() {
    var x = document.forms["frmOrder"]["txtTotal"].value;
    var y = document.forms["frmOrder"]["totalpoints"].value;

    if (x > y) {
        alert("Sorry, you don't have enough points");
        return false;
    }
}

由于某种原因它不起作用.

It's not working for some reason.

如果我执行 alert(x) 我得到 1300，而 alert(y) 得到 999

If I do alert(x) I get 1300, and alert(y) gives 999

这有效....

function validateForm() {
    var x = 1300;
    var y = 999;

    if (x > y) {
        alert("Sorry, you don't have enough points");
        return false;
    }
}

推荐答案

你应该在比较之前将它们转换为数字.

You should convert them to number before compare.

试试:

if (+x > +y) {
  //...
}

或

if (Number(x) > Number(y)) {
  // ...
}

注意: parseFloat 和 pareseInt(比较整数，需要指定radix) 会给你 NaN 一个空字符串，与 NaN 比较总是 false，如果你不想要将空字符串视为 0，然后您可以使用它们.

Note: parseFloat and pareseInt(for compare integer, and you need to specify the radix) will give you NaN for an empty string, compare with NaN will always be false, If you don't want to treat empty string be 0, then you could use them.

这篇关于javascript 如果数字大于数字的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！