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HTML DOM console.assert() Method

❮ Console Object

Example

Write a message to the console, only if the first argument is false:

console.log(document.getElementById("demo"), "You have no element with ID 'demo'");
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Definition and Usage

The console.assert() method writes a message to the console, but only if an expression evaluates to false.


Browser Support

The numbers in the table specify the first browser version that fully supports the method.

Method
console.assert() Yes Yes 28 Yes Yes

Syntax

console.assert(expression, message)

Parameter Values

Parameter Type Description
expression A Boolean expression Required. The message or object to write in the console
message String or Object Required. The message or object to write in the console

More Examples

Example

Write an object to the console:

var myObj = { firstname : "John", lastname : "Doe" };
console.log(myObj);
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Example

Write an Array to the console:

var myArr = ["Orange", "Banana", "Mango", "Kiwi" ];
console.log(myObj);
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❮ Console Object