get a state variable into an array react code example

Example 1: how to add array data on state react

this.setState({ myArray: [...this.state.myArray, 'new value'] }) //simple value
this.setState({ myArray: [...this.state.myArray, ...[1,2,3] ] }) //another array

Example 2: how to update array in react state

this.setState(prevState => ({
  arrayvar: [...prevState.arrayvar, newelement]
}))

Example 3: add items to a react array in hooks

const addMessage = (newMessage) => setMessages(state => [...state, newMessage])

Example 4: add items to a react array in hooks

const addMessage = (newMessage) => setMessages(state => [newMessage, ...state])