HTML DOM console.assert() method

If assert is false ,console.assert()The method will write the error message to the console.

If assert is true, nothing will happen.

Syntax:

console.assert(assertion, 'message')

Example

console.assert(document.getElementById("result"), 'No ID element'result'

All browsers fully support the console.assert() method:

Method
console.assert()	is	is	is	is	is

Parameter	Description
assertion	Any boolean expression. IfassertIf false, the message is written to the console
message	String or object to be written in the console

This example writes a string to the console:

Example

console.assert(false, "Hello world!!!");

This example writes an object to the console:

Example

var myObj = { str: "Some text", id:　12　};
console.assert(document.getElementById("result"), myObj);

This example writes an array to the console:

Example

var arr = ["Item1", "Item2", "Item3", "Item4"];
console.assert(document.getElementById("result"), arr);