# How do I check if a value is an integer in JavaScript?Davide Sconst t="undefined"!=typeof HTMLImageElement&&"loading"in HTMLImageElement.prototype;if(t){const t=document.querySelectorAll("img[data-main-image]");for(let e of t){e.dataset.src&&(e.setAttribute("src",e.dataset.src),e.removeAttribute("data-src")),e.dataset.srcset&&(e.setAttribute("srcset",e.dataset.srcset),e.removeAttribute("data-srcset"));const t=e.parentNode.querySelectorAll("source[data-srcset]");for(let e of t)e.setAttribute("srcset",e.dataset.srcset),e.removeAttribute("data-srcset");e.complete&&(e.style.opacity=1,e.parentNode.parentNode.querySelector("[data-placeholder-image]").style.opacity=0)}}

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(): - The`Number.isInteger()` method checks if a value is an integer. - It returns`true` if the value is an integer, and`false` otherwise.

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const value = 42;
const isInteger = Number.isInteger(value);
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In this example,`Number.isInteger(value)` checks if the`value` is an integer. 2. typeof and Number.isFinite(): - You can combine the`typeof` operator with`Number.isFinite()` to check if a value is both a number and an integer.

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const value = 42;
const isInteger = typeof value === 'number' && Number.isFinite(value) && Math.floor(value) === value;
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In this example,`typeof value === 'number'` checks if the`value` is a number,`Number.isFinite(value)` checks if the number is finite, and`Math.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.

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

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const value = 42;
const isInteger = value % 1 === 0;
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In this example,`value % 1 === 0` checks if the`value` 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.