HTML DOM console.assert()Method
Console ObjectExamples
If the first parameter is false, output information in the console:
console.assert(document.getElementById("demo"), "No element with ID 'demo'");
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Definition and Usage
The console.assert() method outputs information to the console if the first parameter is false.
Syntax
console.assert(expression, message)
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 |
Parameter Description
| Parameter | Type | Description |
|---|---|---|
| Expression | Boolean expression | Required. A boolean expression that returns true or false. |
| Message | String or Object | Required. The message or object to write to the console. |
More Examples
Example
Write an object to the console:
var myObj = { name : "Example", site : "www.example.com" };
console.assert(document.getElementById("demo"), myObj);
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Example
Write an array to the console:
var myArr = ["Google", "Taobao", "Example", "Facebook" ];
console.assert(document.getElementById("demo"), myArr);
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