Bitwise Operator and indexOf on strings

bitwise_indexof.js

// "Bitwise operators perform their operations on such binary representations, but they return standard JavaScript numerical values."

//It transforms -1 into 0, and 0 is false in javascript, so:

var someText = 'text';
!!~someText.indexOf('tex'); //sometext contains text - true
!~someText.indexOf('tex'); //sometext not contains text - false
~someText.indexOf('asd'); //sometext contains asd - false
~someText.indexOf('ext'); //sometext contains ext - true