setState is not updating state properly

Question

Sorry, I really miss something with the transmission of state within props of sub components in React.

I have implemented a version of a todo l

Answer 1

The problem is from Array.push return the number of elements in the array and not the updated array

addTask(task) {
  this.setState({
    tasks: this.state.tasks.push(task)
  })
}

To fix this you can push to state.tasks then setState with it later on:

addTask(task) {
  this.state.tasks.push(task);
  this.setState({
    tasks: this.state.tasks
  })
}

This way you set state.task to the updated array.