39 lines
1.1 KiB
Markdown
39 lines
1.1 KiB
Markdown
---
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title: hexToRGB
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tags: string,math,advanced
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---
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Converts a color code to an `rgb()` or `rgba()` string if alpha value is provided.
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- Use bitwise right-shift operator and mask bits with `&` (and) operator to convert a hexadecimal color code (with or without prefixed with `#`) to a string with the RGB values.
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- If it's 3-digit color code, first convert to 6-digit version.
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- If an alpha value is provided alongside 6-digit hex, give `rgba()` string in return.
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```js
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const hexToRGB = hex => {
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let alpha = false,
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h = hex.slice(hex.startsWith('#') ? 1 : 0);
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if (h.length === 3) h = [...h].map(x => x + x).join('');
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else if (h.length === 8) alpha = true;
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h = parseInt(h, 16);
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return (
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'rgb' +
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(alpha ? 'a' : '') +
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'(' +
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(h >>> (alpha ? 24 : 16)) +
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', ' +
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((h & (alpha ? 0x00ff0000 : 0x00ff00)) >>> (alpha ? 16 : 8)) +
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', ' +
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((h & (alpha ? 0x0000ff00 : 0x0000ff)) >>> (alpha ? 8 : 0)) +
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(alpha ? `, ${h & 0x000000ff}` : '') +
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')'
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);
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};
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```
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```js
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hexToRGB('#27ae60ff'); // 'rgba(39, 174, 96, 255)'
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hexToRGB('27ae60'); // 'rgb(39, 174, 96)'
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hexToRGB('#fff'); // 'rgb(255, 255, 255)'
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```
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