Primitive types
typeof 5 // number
typeof true // boolean
typeof 'wow' // string
typeof undefined // undefined
typeof null // object
typeof Symbol('just me') // symbol since es6
Non-Primitive types
typeof {} // object
typeof [] // object
typeof function(){} // functio
Playground
Primitive is pass by value
In below case, variable a have an address refer to somewhere that memory hold value 5.
let b = a means it will copy value 5, and create a new memory for it to store, then b refer to this new memory location.
let a = 5
let b = a
console.log(a) // 5
console.log(b) // 5
b = 10
console.log(a) // 5
console.log(b) // 10
Non-Primitive is pass by reference
obj2 = obj1 means obj2 will refer to obj1 address.
so that obj1 and obj2 point to the same location where object store in memory
let obj1 = {name:'hui', password:'123'}
let obj2 = obj1
obj2.password = '456'
console.log(obj1) // 456
console.log(obj1) // 456
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