PhantomJS evaluate()

wpage.evaluate(str)

var wpage = require('webpage').create(); 
wpage.open('http://localhost/tasks/test.html', function(status) { 
   var script1 = "function(){ var a = document.title; return a;}"; 
   var value = wpage.evaluate(script1); 
   console.log(value); 
   phantom.exit(); 
});

Welcome to phantomjs

var wpage = require('webpage').create(); 
wpage.onConsoleMessage = function(msg) { 
   console.log('CONSOLE: ' + msg); 
}; 

wpage.open('http://localhost/tasks/test.html', function(status) { 
   var script1 = "function(){ var a = document.title; console.log('hello world');return a;}"; 
   var value = wpage.evaluate(script1); 
   console.log(value); 
   phantom.exit(); 
});

CONSOLE: hello world 
Welcome to phantomjs