How do I check if a value is an integer in JavaScript?
Davide S

In JavaScript, there are multiple approaches to check if a value is an integer. Here are a few methods you can use: 1. Number.isInteger(): - TheNumber.isInteger() method checks if a value is an integer. - It returnstrue if the value is an integer, andfalse otherwise.

1
2
3
4

   const value = 42;
   const isInteger = Number.isInteger(value);

In this example,Number.isInteger(value) checks if thevalue is an integer. 2. typeof and Number.isFinite(): - You can combine thetypeof operator withNumber.isFinite() to check if a value is both a number and an integer.

1
2
3
4

   const value = 42;
   const isInteger = typeof value === 'number' && Number.isFinite(value) && Math.floor(value) === value;

In this example,typeof value === 'number' checks if thevalue is a number,Number.isFinite(value) checks if the number is finite, andMath.floor(value) === value checks if the number is a whole number. 3. Regular expression: - You can use a regular expression to check if a value is in the form of an integer.

1
2
3
4

   const value = '42';
   const isInteger = /^\d+$/.test(value);

Here,/^\d+$/ is a regular expression that matches one or more digits from the start (^) to the end ($) of the string. The.test(value) checks if thevalue matches the regular expression. 4. Modulus operator: - Another approach is to use the modulus operator% to check if a value leaves no remainder when divided by 1.

1
2
3
4

   const value = 42;
   const isInteger = value % 1 === 0;

In this example,value % 1 === 0 checks if thevalue is divisible by 1 without leaving a remainder. Choose the method that best fits your use case and consider the specific requirements of your application. Keep in mind that JavaScript treats all numbers as floating-point values, so be cautious when dealing with integer-like values that may have decimal parts.

Similar Questions