type =“number”但仍需要文本转换为数字

时间:2017-09-11 20:08:08

标签: javascript numbers typeof tofixed

我有一个type = number的元素(x)。在我的工作中,在执行数学运算之前验证它的值是一个数字我得出结论,“数字”类型的元素,虽然具有内置验证和有用的输入控件,仍然将其值分配为文本,并且在执行之前需要转换为数字数学运算。我的问题 - 我的代码是真的还是有问题?这是我的工作。输入数字6.

        x = document.createElement("input");
        x.type = "number";
        x.step = "0.1";
        x.min = "0";
        x.max = "9999";
        x.defaultValue = "1";

var p = document.getElementById(x.id).value;
isThisNumber(p);


function isThisNumber(z) {
    alert(typeof z + " --- " + typeof (z));  // returns "string --- string"

    if (z.isNaN) {
        alert("it's not number");
    } else {
        alert("it's a number");  // returns false - it's a number
    }

    if (z.toFixed) {
        alert("it's a number");
    } else {
        alert("it's not a number");  // returns false - it's not a number
    }

    var a = z + z;
    alert("sum is : " + a);  // returns "66"

    var b = Number(z);
    var b2 = b + b;
    alert("sum is : " + b2);  // returns "12"
}

价: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/input/number

0 个答案:

没有答案