Passing an Object to a function in JavaScript

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If I have the following code, x is initially displayed as an object via typeof(). However, I had assumed objects were passed by reference but the function will not change x. Is this because when it is passed down to the function changestring it is converted to a string data type?

Thanks,

Brian.

<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Untitled Document</title>
<script>
var x = new String("This is a string object");
alert(typeof(x));
changestring(x);
alert(x);

function changestring(x)
{
	x = "Altered String";
}
</script>
</head>

<body>
</body>
</html>

Posted 11-Nov-14 21:56pm

BrianHamilton

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Karthik_Mahalingam · Accepted Answer · 2014-11-11T22:38:00

Solution 1

When passing a a primitive type variable like a string or a number, the value is passed by value. This means that any changes to that variable in the function are completely separate from anything that happens outside the function.

Clear Explanation: Javascript: Pass by reference[^]

Posted 11-Nov-14 22:38pm

Karthik_Mahalingam