Hales_W Hales_W - 1 month ago 5x
Javascript Question

How to make a document.getElementById value into an integer variable, not a string?

I want to pass in a value, obtained from the an html object, convert that value into an integer so I can run arithmetic on it before outputting it. As my code stands now, it just adds them up like a string. So a value of 5 + a modifier of 100 ends up equaling = 5100, not 105.

Here's my form code:

Add Amount: <select id="addTweets">
<option value=5>5</option>
<option value=10>10</option>
<option value=15>15</option>
<input type="button" value="Add It" onclick="addTweet()" />

Here's my script:

function addTweet()
var mod = 100;
var results = document.getElementById("addTweets").value;
results += mod;

document.getElementById("tweetsOutput").innerHTML = results;


The unary plus (+) coerces its operand into a number:

var results = +document.getElementById("addTweets").value;

typeof( results ); // number