Secrets of the Browser Developer Tools

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console.assert() can be used to test whether expressions are true or false.

It takes two parameters: the expression and the message to display. The message will only be shown in the console if the expression is FALSE.

For example, console.assert(!true, 'This is not true'); will output 'This is not true' to the console.While console.assert(true, 'This is not true'); will not output anything to the console.