Pergunta de entrevista da empresa RANDEM IT

What is Interface ? What is Abstract class ? Difference between them ? Database design of online shopping cart. Different questions on design and various modifications. Types of error in PHP ? How to optimize websites ? How to swap 2 number w/o 3rd variable ? Mysql Engines Mysql Index. Disadvantages of it. Various queries (finding duplicate entry, finding 2nd highest entry, etc) Finding 5th child in jQuery