Function console.assert()

The console.assert() methods writes an error
message to the console if the assertion is false.
If the assertion is true, nothing happens.

console.assert(4 > 3, '4 is greater than 3'); // no result
console.assert(3 > 4, '3 is not greater than 4'); // Assertion failed: 3 is not greater than 4
console.assert(i % 2 === 0, { number: i, errorMessage: errorMessage });