how to create react setstate object with array code example

Example 1: Updating an object with setState in React

this.setState(prevState => {
  let jasper = Object.assign({}, prevState.jasper);  // creating copy of state variable jasper
  jasper.name = 'someothername';                     // update the name property, assign a new value                 
  return { jasper };                                 // return new object jasper object
})

//2ND METHOD

this.setState(prevState => ({
    jasper: {                   // object that we want to update
        ...prevState.jasper,    // keep all other key-value pairs
        name: 'something'       // update the value of specific key
    }
}))

Example 2: how to update array in react state

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