Node.js | util.types.isDataView() Method
The util.types.isDataView() method method of util module is primarily designed to support the needs of Node.js own Internal APIs.
The util.types.isDataView() method is used to check if the given value is a DataView object or not.
Syntax:
util.types.isDataView(value)
Parameters: This function accepts one parameter as mentioned above and described below:
- value: It is the value that would be checked for a DataView object.
Return Value: This method returns a Boolean value i.e. true if the passed value is instance of DataView otherwise returns false.
Below programs illustrate the util.types.isDataView() method in Node.js:
Example 1:
Node.js
// Node.js program to demonstrate the // util.types.isDataView() method // Import the util module const util = require( 'util' ); // Checking for a DataView let arraybuf = new ArrayBuffer(5); let dataView = new DataView(arraybuf); console.log( "Value:" , dataView); isDataView = util.types.isDataView(dataView); console.log( "Value is a DataView:" , isDataView); // Checking for an Integer array let intArray = new Int32Array(); console.log( "Value:" , intArray); isDataView = util.types.isDataView(intArray); console.log( "Value is a DataView:" , isDataView); |
Output:
Value: DataView { byteLength: 5, byteOffset: 0, buffer: ArrayBuffer { [Uint8Contents]: <00 00 00 00 00>, byteLength: 5 } } Value is a DataView: true Value: Int32Array [] Value is a DataView: false
Example 2:
Node.js
// Node.js program to demonstrate the // util.types.isDataView() method // Import the util module const util = require( 'util' ); // Creating an unsigned integer 8-bit array let int8Array = new Uint8Array([10, 20, 30]); console.log( "Value:" , int8Array); // Checking for a view console.log( "Value is a View:" , ArrayBuffer.isView(int8Array)); // Checking for a DataView isDataView = util.types.isDataView(int8Array); console.log( "Value is a DataView:" , isDataView); // Creating a dataview let dataView = new DataView( new ArrayBuffer(3)); dataView.setUint8(0, 10); dataView.setUint8(1, 20); dataView.setUint8(2, 30); console.log( "Value:" , dataView); // Checking for a view console.log( "Value is a View:" , ArrayBuffer.isView(dataView)); // Checking for a DataView isDataView = util.types.isDataView(dataView); console.log( "Value is a DataView:" , isDataView); |
Output:
Value: Uint8Array [ 10, 20, 30 ] Value is a View: true Value is a DataView: false Value: DataView { byteLength: 3, byteOffset: 0, buffer: ArrayBuffer { [Uint8Contents]: <0a 14 1e>, byteLength: 3 } } Value is a View: true Value is a DataView: true
Reference: https://nodejs.org/api/util.html#util_util_types_isdataview_value
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