25 lines
890 B
Markdown
25 lines
890 B
Markdown
---
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title: reverseNumber
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tags: number,array,beginner
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---
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Reverses a number.
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Use `Object.prototype.toString()` to convert number to a string.
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Use the split function `String.prototype.split()` to convert string to array and `Array.prototype.reverse()` to reverse the order of the characters in the string.
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Combine characters to get a string using `String.prototype.join('')`.
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Use the `parseFloat()` to convert string to a number and use `Math.sign()` to preserve the signum value of the number.
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_Note_: Here `parseFloat()` is used instead of `parseInt()` so floating point numbers are properly handled.
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```js
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const reverseNumber = n => {
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const reveresedNumber = n.toString().split('').reverse().join('');
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return parseFloat(reveresedNumber) * Math.sign(n);
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}
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```
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```js
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reverseNumber(981); // 189
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reverseNumber(-500); // -5
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reverseNumber(73.6); // 6.37
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reverseNumber(-5.23); // -32.5
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``` |