window.onload = function() { document.getElementById("typeof").style.backgroundColor = "#222" document.getElementById("typeof").style.color = "#fff" }; class Obj {} var a = new Obj (); function b() {} var c = [1,2,3].constructor var d = function () { return; 4} var e = new function () {} function f() { var nothing = function () { document.write("clean code") } } var g = "5" let h = 5 const j = {} const k = null const m = undefined document.write('1. typeof a in (var a = new Obj ())
//outputs ' + typeof a + "
" + "
") document.write('2. typeof Obj in (class Obj {})
//outputs ' + typeof Obj + "
" + "
") document.write('3. typeof b in (function b() {})
//outputs ' + typeof b + "
" + "
") document.write('4. typeof b() in (function() {})
//outputs ' + typeof b() + "
" + "
") document.write('5. typeof constructor in ([1,2,3].constructor)
//outputs ' + typeof constructor + "
" + "
") document.write('6. typeof c in (var c = [1,2,3].constructor)
//outputs ' + typeof c + "
" + "
") document.write('7. typeof d in (var d = function () { return; 4})
//outputs ' + typeof d + "
" + "
") document.write('8. typeof d() in (var d = function () { return; 4})
//outputs ' + typeof d() + "
" + "
") document.write('9. typeof e in (var e = new function () {
function f() { var nothing = function () {
document.write("clean code") }})
//outputs ' + typeof e + "
" + "
") document.write('10. typeof f() in (var e = new function () {
function f() { var nothing = function () {
document.write("clean code") }})
//outputs ' + typeof f() + "
" + "
") document.write('11. typeof g in (var g = "5")
//outputs ' + typeof g + "
" + "
") document.write('12. typeof h in (let h = 5)
//outputs ' + typeof h + "
" + "
") document.write('13. typeof j in (const j = {})
//outputs ' + typeof j + "
" + "
") document.write('14. typeof k in (const k = null)
//outputs ' + typeof k + "
" + "
") document.write('15. typeof m in (const m = undefined)
//outputs ' + typeof m + "
" + "
")

Data types in JS