[Use new JS syntax/features PLEASE] #javascript

index.md

Array

ES5 provides follow some useful Array methods, these are all available in modern browsers(>= IE9):

• Array.isArray
• Array.prototype.forEach
• Array.prototype.map
• Array.prototype.every
• Array.prototype.some
• Array.prototype.filter
• Array.prototype.reduce
• Array.prototype.reduceRight
• ...

These methods are good at semantic, So use them instead of unreadable and long for-loop:

const arr = [balabala...]
const filtered = []
for(let i = 0; i < arr.length; i++) {
	if (some-condition) {
    	filtered.push(arr[i])
    }
}

// better
const arr = [balabala...]
const filtered = arr.filter((item) => some-condition)

In addition, ES6(2015) provides:

• Array.from
• find
• keys
• values
• entries
• fill

and ES7(2016) provides:

• includes

Not all browsers supported these methods natively, but you can use them through babel or polyfills.

if (arr.indexOf(item) !== -1) {...}

// better
if (arr.includes(item)) {...}