for
, , .for
(. mutation of state — — . ) (. side effects — — . ), .for
, .const cats = [
{ name: 'Mojo', months: 84 },
{ name: 'Mao-Mao', months: 34 },
{ name: 'Waffles', months: 4 },
{ name: 'Pickles', months: 6 }
]
var kittens = []
// , for
for (var i = 0; i < cats.length; i++) {
if (cats[i].months < 7) {
kittens.push(cats[i].name)
}
}
console.log(kittens)
const isKitten = cat => cat.months < 7
var kittens = []
for (var i = 0; i < cats.length; i++) {
if (isKitten(cats[i])) {
kittens.push(cats[i].name)
}
}
isKitten
, , .const isKitten = cat => cat.months < 7
const getName = cat => cat.name
var kittens = []
for (var i = 0; i < cats.length; i++) {
if (isKitten(cats[i])) {
kittens.push(getName(cats[i]))
}
}
filter
map
, , , (filter
map
— . ) . , .const isKitten = cat => cat.months < 7
const getName = cat => cat.name
const kittens =
cats.filter(isKitten)
.map(getName)
kittens.push(...)
. var
.const
var
let
const
, ( ), , !const isKitten = cat => cat.months < 7
const getName = cat => cat.name
const getKittenNames = cats =>
cats.filter(isKitten)
.map(getName)
const cats = [
{ name: 'Mojo', months: 84 },
{ name: 'Mao-Mao', months: 34 },
{ name: 'Waffles', months: 4 },
{ name: 'Pickles', months: 6 }
]
const kittens = getKittenNames(cats)
console.log(kittens)
break
”, “ JavaScript: break GOTO ”.for
?Source: https://habr.com/ru/post/329004/
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