Methods - Array - array.splice(startIndex, deleteCount, replace/add) array.reverse() array.join() array.concat(array) For loop: for(const i of nums) forEach( Hoisting in javascript Variable types: var - function-scope let - block-scoped variable (accessible inside the block variable is defined) , can not be accessed before initialization. const Java Script with ES6 (Modern day way to code in Java Script) - Template literal eg.: `Hello ${userName}!` - parseInt - convert to number from string type of numbers -parseFloat -typeof - provide the type equality or strict equality - == Vs === (value only Vs value + type) Ternery Operator: condition ? expIfTrue : expIfFalse