Conversion rules for Boolean type?

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What are the ways to convert js to Boolean type?

1. Use the Boolean() function

let str = '1234'
console.log(Boolean(str));//true
let str1 = null
console.log(Boolean(str1));//false

2.!!value

let str = '1234'
console.log(!!str);//true
let str1 = null
console.log(!!str1);//false

3.value ? true :false

let str = '1234'
console.log(str?true:false);//true
let str1 = null
console.log(str1?true:false);//false

Conversion rules for Boolean type?

Boolean type conversion has only two results, true and false

false value

• undefined
• null
• false
• +0, -0 sum NaN
• “”

These converted to Boolean types are all false

true value

Except for the false values ​​introduced above, all of them are true when converted into Boolean types