JavaScript gives a message if it encounters an error. The recognized errors are -

► Load-time errors: The errors shown at the time of the page loading are counted under Load-time errors. These errors are encountered by the use of improper syntax, and thus are detected while the page is getting loaded.

► Run-time errors: This is the error that comes up while the program is running. It is caused by illegal operations, for example, division of a number by zero, or trying to access a non-existent area of the memory.

► Logic errors: It is caused by the use of syntactically correct code, which does not fulfill the required task. For example, an infinite loop.