SOURCE

// string number boolean null undefined function array object 
function type(obj){
    if(obj === null)return String(obj)
    // console.log(typeof obj)
    return typeof obj === 'object'? Object.prototype.toString.call(obj).replace('[object ','').replace(']','').toLowerCase() : typeof obj 
}
console.log(type(1))
console.log(type(''))
console.log(type(true))
console.log(type(null))
console.log(type(()=>{}))
console.log(type([]))
console.log(type({}))
console.log(type(/1/))
console.log(type(new Date()))