Internal Logics Behind Javascript Array Methods

Array join() It combines all the elements of an array into a single string.It allows us to specify our own separator between the elements. const myArr = [ " HTML " , " CSS " , " JS " ]; function joinDemo ( arr , separator ){ let result = "" ; for ( let i = 0 ; i < arr . length ; i ++ ){ result += arr [ i ]; if ( i < arr . length - 1 ){ result += separator ; } } return result ; } console . log ( joinDemo ( myArr , " - " )); //HTML-CSS-JS Built-in Logic const arr = [ " HTML " , " CSS " , " JS " ];