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JavaScript Number method: isSafeInteger()

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The isSafeInteger() method (of the JavaScript Number object) returns true if value is of type Number and is a safe integer, otherwise false. A safe integer is one that can be exactly represented as an IEEE-754 double precision number, i.e. is an integer in the range -(253 - 1) to (253 - 1).

 

It has the following syntax with the following parameters:

 

Number.isSafeInteger(x)

 

Parameter

Required / Optional

Description

x

Required

Input parameter

 

EXAMPLE:


HTML USED IN THIS EXAMPLE:
<!DOCTYPE html>
<html> <!-- Copyright (c) Nematrian Limited 2018 -->
<head>
<style>
table,th,tr,td {border: 1px solid black; border-collapse: collapse;}
</style>
</head>
<body>
<table>
<tr>
<th>Example</th>
<th>Resulting value of <code>x</code></th>
</tr>
<tr>
<td><code id="Example"></code></td>
<td><code id="Result"></code></td>
</tr>
</table>

<script>
document.getElementById("Example").innerHTML =
  'var x = Number.isSafeInteger(1e160-1);';
document.getElementById("Result").innerHTML =
  Number.isSafeInteger(1e160-1);
</script>

</body>
</html>

FUNCTION THAT MAY ASSIST IN TESTING WHETHER FEATURE IS SUPPORTED:
function isSupportedJavaScriptMethodNumberIsSafeInteger() {
  var z = 12.5; return !!z.isSafeInteger;
}


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