JAVASCRIPT

react state add to array

// Save search term state to React Hooks with spread operator and wrapper function

// Using .concat(), no wrapper function (not recommended)
setSearches(searches.concat(query))

// Using .concat(), wrapper function (recommended)
setSearches(searches => searches.concat(query))

// Spread operator, no wrapper function (not recommended)
setSearches([...searches, query])

// Spread operator, wrapper function (recommended)
setSearches(searches => [...searches, query])

add new array at the back of react state

this.setState(prevState => ({
  myArray: [...prevState.myArray, "new value"]
}))

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

add new array at the back of react state

this.setState(prevState => ({
  myArray: ["new value", ...prevState.myArray]
}))

add new array at the back of react state

this.setState(prevState => ({
  myArray: [...prevState.myArray, {"name": "object"}]
}))

add object in array state react

const handleAdd = (todo) => {
  const newTodos = [...todos];
  newTodos.push(todo);
  setTodos(newTodos);
}

add object in array state react

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

add new array at the back of react state

this.setState(prevState => ({
  myArray: [ {"name": "object"}, ...prevState.myArray]
}))

add array of object to state react

var joined = this.state.myArray.concat('new value');
this.setState({ myArray: joined })