javascript tips

連番

IEだとspread syntaxが使えないから無理　forで配列に足し込んでくぐらいしかできない

code:js

// 0〜59

// 1〜60

const minitues = ...Array(60).keys().map(i => ++i)

code:javascript

let minutes = []

for (let i = 1; i <= 60; i++) {

minutes.push(i)

}

Nodelist.forEach()をIEで使用

code:javascript

const _nodes = document.querySelectorAll('.example')

const nodes = Array.prototype.slice.call(_nodes, 0)

tail :: [a] -> [a] 風の操作

code:javascript

const head = arr0

const tail = arr.slice(1)

↑を使って再帰

code:typescript

const add = (num1: number) => (num2: number) => num1 + num2

const recursiveApply = (num: number, fns: ((a: number) => number)[]): number => {

if (fns.length === 0) {

return num

}

return recursiveApply(fns0(num), fns.slice(1))

}

const result = recursiveApply(1, fns)

console.log(result) // => 7

select要素の選択されているoptionを取得(IE対応)

code:javascript

const select = document.querySelector('#select')

const selectedOption = select.optionsselect.selectedIndex

個別ページ作ったやつ

Polyfillが必要なときに使ってみたいPolyfill.io

大体なんとかなった

非破壊的reverse

code:javascript

const reverse = arr.slice().reverse()