SOURCE

let a={id:1,name:'1'}
let b={id:1,name:'1'}
console.log(a==b)

let map = new Map()
map.set(a,1)
map.set(a,2)
map.set(b,3)

console.log(map.size)

const a1=''
//const a1=null

console.log(!a1)

if (a1){
    console.log('a1 is not empty')
}
else{
    console.log('a1 is empty')
}

let flag1=0
if (flag1){
    console.log('flag1==0 相当于 true')
}
else{
    console.log('flag1>0 相当于 true')
}

let status=undefined
if (status==="complete"){
    console.log("status==complete")
}
else{
    console.log("status!=complete")
}

let setting = ''
if (setting){
    console.log('if (setting)==true')
}
else{
    console.log('if (setting)==false')
}

setting = '{}'
const obj = JSON.parse(setting)
if (obj){
    console.log('if (obj) == true')
}
else{
    console.log('if (obj) == false')
}