Issue: Error thrown due to attempting to access the 'push' property of an undefined element in an Angular child component

I have an array in my child component's element

  @Input() listAnswer: any;

  changestyle(event)
  {
   let activeSpan = event.target;
   this.listAnswer.push(activeSpan.innerText.trim());
  }

I am passing this variable from the parent component

<app-child [listAnswer]="listAnswer"></app-child>

However, I encountered the following error:

ERROR TypeError: Cannot read properties of undefined (reading 'push')

This code was functioning correctly in the main component. Any suggestions? Thank you.

Answer №1

When setting up your component.ts file, make sure to initialize some values for the listAnswer input declaration. For example:

  @Input() listAnswer: any[]=[];

Answer №2

It is important to ensure that your listanswer variable is declared as an array:

@Input listAnswer: any[];

Additionally, the parent component must also have its listAnswer property defined as an array type.

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