what is the difference between getDefaultProps and getInitialState react js

Question

I am new in react js.

getDefaultProps () {
    return {
        backgroundColor: 'gray',
        height: 200,
        width: 200
    }
},

I've same values for getDefaultProps and for getInitialState :

getInitialState () {
    return {
        backgroundColor: 'gray',
        height: 200,
        width: 200
    }
},

What is the logical difference in between both. which should supposed to override or which one will execute first.

Thanks.

Answer 1

getInitialState

• The object **getInitialState()** Invoked once before the component is mounted. The return value will be used as the initial value of this.state.

Note: This method is not available on ES6 class components that extend React.Component. For more information, please read our documentation about ES6 classes.

getDefaultProps

• The object **getDefaultProps()** Invoked once and cached when the class is created. Values in the mapping will be set on this.props if that prop is not specified by the parent component (i.e. using an in check).
• This method is invoked before any instances are created and thus cannot rely on this.props. In addition, be aware that any complex objects returned by getDefaultProps() will be shared across instances, not copied.