javascript bang bang operator code example
Example 1: es6 what is double exclamation operator
!oObject // inverted boolean
!!oObject // non inverted boolean so true boolean representation
Example 2: javascript operator double not
// convert to boolean
// The following examples are the only values which result in a false expression
!!0 // false
!!"" // false
!!null // false
!!undefined // false
!!NaN // false