ControlArray

Defines a part of a form, of variable length, that can contain other controls.

A ControlArray aggregates the values of each Control in the group. The status of a ControlArray depends on the status of its children. If one of the controls in a group is invalid, the entire array is invalid. Similarly, if a control changes its value, the entire array changes as well.

ControlArray is one of the three fundamental building blocks used to define forms in Angular, along with Control and ControlGroup. ControlGroup can also contain other controls, but is of fixed length.

Adding or removing controls

To change the controls in the array, use the push, insert, or removeAt methods in ControlArray itself. These methods ensure the controls are properly tracked in the form's hierarchy. Do not modify the array of AbstractControls used to instantiate the ControlArray directly, as that will result in strange and unexpected behavior such as broken change detection.