30 lines
805 B
Markdown
30 lines
805 B
Markdown
---
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title: toOrdinalSuffix
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tags: math,intermediate
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firstSeen: 2017-12-17T17:55:51+02:00
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lastUpdated: 2020-11-13T19:49:57+02:00
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---
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Takes a number and returns it as a string with the correct ordinal indicator suffix.
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- Use the modulo operator (`%`) to find values of single and tens digits.
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- Find which ordinal pattern digits match.
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- If digit is found in teens pattern, use teens ordinal.
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```js
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const toOrdinalSuffix = num => {
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const int = parseInt(num),
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digits = [int % 10, int % 100],
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ordinals = ['st', 'nd', 'rd', 'th'],
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oPattern = [1, 2, 3, 4],
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tPattern = [11, 12, 13, 14, 15, 16, 17, 18, 19];
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return oPattern.includes(digits[0]) && !tPattern.includes(digits[1])
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? int + ordinals[digits[0] - 1]
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: int + ordinals[3];
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};
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```
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```js
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toOrdinalSuffix('123'); // '123rd'
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```
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