JAVASCRIPT

javascript Spread Operator with Object

const obj1 = { x : 1, y : 2 };
const obj2 = { z : 3 };

// add members obj1 and obj2  to obj3
const obj3 = {...obj1, ...obj2};

console.log(obj3); // {x: 1, y: 2, z: 3}

object spread method

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
})

object spread 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
    }
}))

Spread Syntax for object

let objClone = { ...obj }; // pass all key:value pairs from an object