Javascript adding numbers as strings

问题

I have the following code which interprets the numbers as strings and adds them like 100300 instead of 400:

var rate = document.getElementById('pur_price').value;
var pprice = document.getElementById('pur_price').value;
var rate1 = document.getElementById('select2').value;
var refurb = 300;
document.getElementById('avg_claim_rate').value=id;
document.getElementById('amount_claim').value=pprice+refurb;

it's the pprice and refurb field, so if pprice=100 and refurb=300, I expect it to show 400, where as at the moment it shows 100300

回答1:

var result = +pprice + + refurb;

回答2:

You can use parseInt function:

var pprice = parseInt(document.getElementById('pur_price').value, , 10);
var rate1 = parseInt(document.getElementById('select2').value, , 10);

回答3:

Use function parseInt() it can be:

document.getElementById('avg_claim_rate').value=id;
document.getElementById('amount_claim').value=parseInt(pprice)+refurb;

回答4:

As @sergio said, you can use JavaScript's built in parseInt function. Just for reference, you can multiply it by one. JavaScript always converts a string to a number if you multiply it. So you could do something like this:

var num1 = "300";
var num2 = "100";

var num1 = num1 * 1; // Converts string to the number 300
var num2 = num2 * 1;

document.getElementById('number').value = num1+num2;

<input id="number"/>

This is just an alternate way to do the same thing. Use whatever is easiest for you. Hope that helps!

来源：https://stackoverflow.com/questions/26866468/javascript-adding-numbers-as-strings

标签

javascript

variables

math

addition