W3 school is well formated and well designed website for a beginner programming. Due to well formated its easy to learn . It also provide examples assignments after every topic . They have explained in a simplest language so that beginners should understand. It helps to improves reading and basic understanding. We can learn freely but to get certified they charges you. Their are quizzes and lots of exercise . But they cant warrant you full correctness of all content. I have done my base strong through this website.