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Can re-declaring a variable destroy the value of that variable in JavaScript?
Re-declaring a variable will not destroy the value of a variable, until and unless it is assigned with some other new value.
If we look at the following example variables "x" and ''y'' were assigned with values 4 and 8 respectively, later on when those variables were reassigned, the old values were replaced with the new values and displayed as shown in the output.
Example
<html>
<body>
<script>
var x = new Number(4);
var x = 7;
var y = 8;
var y = 10;
document.write(x);
document.write("</br>");
document.write(y);
</script>
</body>
</html>Output
7 10
In the following example, the variables were re-declared, but their values were not reassigned. Therefore those variables retained their original values.
Example
<html>
<body>
<script>
var x = new Number(4);
var x;
var y = 8;
var y;
document.write(x);
document.write("</br>");
document.write(y);
</script>
</body>
</html>Output
4 8
Updated on: 29-Jun-2020
208 Views
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