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const reverseInt = int => {\n  // convert the number to a string\n  const toStr = int.toString()\n\n  // reverse the string\n  const strReversed = toStr.split("").reverse().join("")\n\n  // convert the reversed string to a number\n  const intReversed = Number.parseInt(strReversed, 10)\n\n  // If int is positive, then return the number; otherwise, return the number multiplied by -1\n  return intReversed * Math.sign(int)\n}\n\nconsole.log(reverseInt(514))\n// 415\n\nconsole.log(reverseInt(-500))\n// -5
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Number.parseInt()

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Number.parseInt(string, radix)
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The Number.parseInt() method parses a string argument and returns an integer of the specified radix (base).

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radix

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Any number system with radix (or base), r consists of 0 to r-1 symbol to represent any number. For example, decimal number system having radix, r-10, uses 0 to 9 numbers.

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If radix is undefined or 0, it is assumed to be 10.

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// radix is assumed to be 10\nconst num = Number.parseInt("340")\n\nconsole.log(num)\n// 340\n\nconsole.log(typeof num)\n// number
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Math.sign()

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The Math.sign() function returns 1 if the argument is positive, -1 if the argument is negative, 0 if the argument is positive zero, -0 if the argument is negative zero, NaN if otherwise.

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console.log(Math.sign(2))\n//  1\n\nconsole.log(Math.sign(-5))\n//  -1\n\nconsole.log(Math.sign(0))\n//  0\n\nconsole.log(Math.sign(-0))\n//  -0
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Learn how to reverse a string in my blog post here.
\n","frontmatter":{"title":"How to Reverse An Integer In JavaScript?","date":"2021-07-14"}}},"pageContext":{"slug":"/how-to-reverse-an-integer-in-javascript/","prev":{"fields":{"slug":"/how-to-find-out-the-most-common-character-in-a-string-in-javascript/"},"frontmatter":{"modules":null}},"next":{"fields":{"slug":"/3-ways-to-reverse-a-string-in-javascript/"},"frontmatter":{"modules":null}}}}, "staticQueryHashes": ["3159585216"]}