DOMMatrixReadOnly: isIdentity property

{{APIRef("Geometry Interfaces")}}{{AvailableInWorkers}}

The readonly isIdentity property of the {{domxref("DOMMatrixReadOnly")}} interface is a Boolean whose value is true if the matrix is the identity matrix.

The identity matrix is one in which every value is 0 except those on the main diagonal from top-left to bottom-right corner (in other words, where the offsets in each direction are equal).

Value

A Boolean value.

Examples

// Initialize a 2D matrix
const matrix = new DOMMatrix(); // create a matrix
console.log(matrix.isIdentity); // output: true

// Apply a transform that has no effect
console.log(matrix.translate(0).isIdentity); // output: true

// Apply a transform with effect: this rotates the matrix by 30deg
console.log(matrix.rotate(30).isIdentity); // output: false

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• {{domxref("DOMMatrix")}} interface
• {{domxref("CSSMatrixComponent")}} interface
• {{domxref("CanvasRenderingContext2D")}} interface
• CSS {{cssxref("transform-function/matrix()")}} function
• CSS {{cssxref("transform")}} property
• CSS transforms module
• SVG transform attribute