var VerEx = require("verbal-expressions");

// Create an example of how to test for correctly formed URLs
var tester = VerEx()
            .startOfLine()
            .then( "http" )
            .maybe( "s" )
            .then( "://" )
            .maybe( "www." )
            .anythingBut( " " )
            .endOfLine();

// Create an example URL
var testMe = "https://www.google.com";

// Use RegExp object's native test() function
if( tester.test( testMe ) ) alert( "We have a correct URL "); // This output will fire
else alert( "The URL is incorrect" );

console.log( tester ); // Ouputs the actual expression used: /^(http)(s)?(\:\/\/)(www\.)?([^\ ]*)$/ 

// Create a test string
var replaceMe = "Replace bird with a duck";

// Create an expression that seeks for word "bird"
var expression = VerEx().find( "bird" );

// Execute the expression like a normal RegExp object
var result = replaceMe.replace( expression, "duck" );

alert( result ); // Outputs "Replace duck with a duck"

var result = VerEx().find( "red" ).replace( "We have a red house", "blue" );
alert( result ); // Outputs "We have a blue house"