Can not get correct clientWidth or clientHeight with react ref

Question

constructor(props) {
    super(props)
    this.ref = React.createRef()
}

componentDidMount() {
    const { clientWidth, clientHeight } = this.ref.current
    console.log(this.ref.current)
    console.log(clientWidth, clientHeight)
}

render() {
    return (
        <div ref={this.ref} style={{width: '100%', height: '100%'}}></div>
    )
}

I want to get width and height of an element

The first log contains correct values

But the second log says different

Why?

first log:

clientHeight:783
clientLeft:0
clientTop:0
clientWidth:1385

second log:

1920 248

Answer 1

Now I have figured it out, chrome console log sometime is very slow, by the time it logs, the width and height already changed.