CODEWITHSUNDEEP
javascripthtml
Sudhakar S
Sudhakar S

Reputation: 385

issue with comparing two numbers in javascript

my html code is like:

<html>
<SCRIPT type="text/javascript" language="JavaScript">   
function fun()
{
var l = document.test.low.value;
var h = document.test.high.value;
alert(l);
alert(h);
    if(l >h){
        alert("low greater than high low is -"+l+"high is -"+h);
    }
}
</SCRIPT>

<body>

<form name="test">
<input type="text" size="11" id="low" />
<input type="text" size="11" id="high" />
<input type="button" value="sss" onClick="fun()"/> 
</form>
</body>
</html>

when i compare this two values using low is 12 and high is 112 is not working. like 22 and 122, 33 and 133 etc....

I am using IE browser version 8. please help.

Upvotes: 18

Views: 94102

Answers (5)

Pranav
Pranav

Reputation: 8871

Convert the values to numbers:

if(Number(l) > Number(h)){ /* … */ }

or alternatively, parse each string as a float:

if(Number.parseFloat(l) > Number.parseFloat(h)){ /* … */ }

or as an integer:

if(Number.parseInt(l, 10) > Number.parseInt(h, 10)){ /* … */ }

Upvotes: 32

vireshas
vireshas

Reputation: 816

When you compare two strings in an if statement: 

if ( l > h) {}    
when l = "12" and h = "112"

It compares these two values as strings as "3" > "1". It says l > h is true

Upvotes: 0

Lokesh
Lokesh

Reputation: 21

var lnum = new Number(l);
var hnmu = new Number(h);
if(lnum > hnum){
alert('if');

}else{
alert('else');
}

Upvotes: 1

Sarfraz
Sarfraz

Reputation: 382606

Use parseInt with base to get correct results:

var l = parseInt(document.test.low.value, 10);
var h = parseInt(document.test.high.value, 10);

Upvotes: 6

Shadow Wizard
Shadow Wizard

Reputation: 66389

You need to convert them to numbers:

if(+l > +h){

The unary plus operator will convert the string value to numeric value. See this question for more details:
What's the significant use of unary plus and minus operators?

Live example.

Upvotes: 11

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