alert("Hello JavaScript");

Question

The same function can be achieved without alert("Hello JavaScript");. Why must this code be added?

有人@我 · Answer

It is only used for debugging the code. You can also use console.log. Alert also has a function, which is to give prompt information to website users when they click certain buttons or information, so that users know where the operation is wrong. However, Nowadays, everyone uses layer pop-ups

nearest · Answer

Is to test whether your js is executed normally

路过 · Answer

This is debugging information, delete it if you are sure the program is useless