JS auto increment and auto decrement (unary operator)

Unary operator ：
You can use + Number , take string -> number

let a = '123'
a = +a
console.log(a,typeof a) // 123 'number'

Self increasing ：

let a = 1
console.log(a++)  //1 
console.log(`a=${a}`) //a=2 

let a = 1
console.log(++a) //2
console.log(`a=${a}`) //a=2 

let d = 20
d =d++
console.log(d)  //20

Self reduction :

let a = 3
console.log(a--); // 3
console.log(a) // 2

let b = 3
console.log(--b); // 2
console.log(b); //2