How to make your JS Code more readable and JavaScript code easier to read

How to make your JS Code more readable and JavaScript code easier to read

As a JS programmer, if the code written by myself looks nice and easy to read, it will not only look nice to myself, but it will be very smooth after other programmers take over the work.

Do not leave a large comment in the code

Leave it to git for management. What else do you want git to do?

// bad// function add() {// const a = b + c// return a// }function add() { return a + 1000}// goodfunction add() { return a + 1000}

Line feed as appropriate

// badfunction a() { const { state_a, state_b, state_c } = this.state this.setState({state_a: state_a * 2}) return 'done'}// goodfunction a() { const { state_a, state_b, state_c } = this.state this.setState({state_a: state_a * 2}) return 'done'}

Add comments as appropriate, but do not add comments as crazy.

Comments to a piece of code or a line of code that requires special attention

Don't comment crazy. It's too cool. Pretty code can speak on its own.

// Badconst a = 'A' // This is aconst B = 'B' // This is bconst c = 'C' // This is c // good/*** declarative variable * /const a = 'A' const B = 'B' const c = 'C'

Classify code with similar behaviors and names

// badfunction handleClick(arr) { const a = 1 arr.map(e => e + a) const b = 2 return arr.length + b}// goodfunction handleClick(arr) { const a = 1 const b = 2 arr.map(e => e + a) return arr.length + b}

In the case that semantics is not damaged, 'saving is saved'

Remember that functions in JavaScript are first-class citizens.

However, if it is omitted to affect readability, it will fail.

If you must select either readability or conciseness, always select readability first.

function add(a) { return a + 1}function doSomething() {}// badarr.map(a => { return add(a)})setTimeout(() => { doSomething()}, 1000)// goodarr.map(add)setTimeout(doSomething, 1000)

Arrow Function

// badconst a = (v) => { return v + 1}// goodconst a = v => v + 1// badconst b = (v, i) => { return { v, i }}// goodconst b = (v, i) => ({v, i})// badconst c = () => { return (dispatch) => { // doSomething }}// goodconst c = () => dispatch => { // doSomething}

Get the object values in advance (react users must understand)

// badconst a = this.props.prop_a + this.props.prop_bthis.props.fun()// goodconst { prop_a, prop_b, fun} = this.propsconst a = prop_a + prop_bfun()

Rational use of various expressions

// badif (cb) { cb()}// goodcb && cb()// badif (a) { return b} else { return c}// goodreturn a ? b : c// badif (a) { c = a} else { c = 'default'}// goodc = a || 'default'

Method of chained call

// badfetch(url).then(res => { return res.json()}).then(() => { // doSomething}).catch(e => {})// goodfetch(url) .then(res => { return res.json() }) .then(() => { // doSomething }) .catch(e => { })

Keep code vertically developed

We should consider wrapping the code that is particularly 'paint' in the entire file.

// badreturn handleClick(type, key, ref, self, source, props)// goodreturn handleClick( type, key, ref, self, source, props)// badconst a = this.props.prop_a === 'hello' ? <di>world</div> : null// goodconst a = this.props.prop_a === 'hello' ? <di>world</div> : null