31 lines
441 B
Markdown
31 lines
441 B
Markdown
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---
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title: padStartにおけるpadSizeの求め方
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---
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$$
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\textrm{padSize} = \lceil \log_{10}(\mathbf{arraySize} + 1) \rceil
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$$
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```js
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const padSize = Math.ceil(Math.log10(arr.length + 1))
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arr.forEach(async (item, index) => {
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console.log(`${index.padStart(padSize, '0')}: ${item}`)
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})
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```
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結果は以下のようになる。
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```
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01: item1
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02: item2
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03: item3
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04: item4
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05: item5
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06: item6
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07: item7
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08: item8
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09: item9
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10: item10
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```
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