Javascript 如何在Javascript中.substr()一个整数

How to .substr() a integer in Javascript

提问by Allen Gingrich

As the title says, which function will give me a result similar to what .substr() does, only for integers?

正如标题所说，哪个函数会给我类似于 .substr() 所做的结果，仅适用于整数？

Thanks!

谢谢！

UPDATE:

更新：

Here is what isn't working:

这是不起作用的：

if ($(#itemname).val() == "Not Listed") {

        var randVal = Math.random() * 10238946;

        var newVal = randVal.toString().substr(0, 4);

        $("#js_itemid").val(randVal);

        $("#js_price").val("199.99");

    }

回答by svanryckeghem

What about ...

关于什么 ...

var integer = 1234567;
var subStr = integer.toString().substr(0, 1);

... ?

……？

回答by vol7ron

Given

给定的

var a = 234; 

There are several methods to convert a number to a string in order to retrieve the substring:

有几种方法可以将数字转换为字符串以检索子字符串：

• string concatenation
• Number.prototype.toString() method
• template strings
• String object

• 字符串连接
• Number.prototype.toString() 方法
• 模板字符串
• 字符串对象

---

---

Examples

例子

Included are examples of how the given number, a, may be converted/coerced.

包括如何a转换/强制给定数字的示例。

Empty string concatenation

空字符串连接

(a+'').substr(1,1);        // "3"

Number.prototype.toString method

Number.prototype.toString 方法

a.toString().substr(1,1)   // "3"

Template strings

模板字符串

`${a}`.substr(1,1)         // "3"

String object

字符串对象

String(a).substr(1,1)      // "3"

回答by STW

Would converting to a string first be ok?

首先转换为字符串可以吗？

var x = 12345;
var xSub = x.toString().substr(1,3);

alert(xSub);? // alerts "234"

回答by Gabriele Petrioli

You should convert it to string first with toString()

您应该先将其转换为字符串 toString()

var a = 105;

alert(a.toString().substr(1,2));

回答by Leandro Rodrigues Combinato

You might want to try this:

你可能想试试这个：

<script>
var x = '146870';

    function format(num){
        return (num / 100).toFixed(2);
    }

    alert(format(x));
</script>