Reactjs map works but forEach doesn't

The map function returns an array of items and forEach just loop over them. To make this code work use :

render() {    
  const items = [];
  this.props.items
    .forEach(item => items.push(
                       <li>
                          <TodoItem id={item.id} key={item.id} text={item.text} />
                       </li>
                     ))

  return(
     <ul>{items}</ul>
  );
}

Try this simple example for understand why forEach doesn't work in this context:

[1,2,3].forEach((n)=> n); => returns undefined

[1,2,3].map((n)=> n); => returns [1,2,3]

As @Nenad Vracar mentioned map will actually return stuff. If you wanted to do somethings to another array, object or piece of code you could use forEach. But since you want to return something that ends up being shown on the DOM. Use map.

Also, don't forget to return whatever you're mapping. It's a common mistake because you don't need to use the return for forEach.

Reactjs map works but forEach doesn't

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