There are two ways of doing so. If we have have a class based component that contains an array of names in the state like :
state =
{ names:['liz', 'liza', 'blue']}
We could create a function below the state, and before the render method to display the names only if the length is greater than zero:
renderNames(){
if
(this.state.names.length ===0) return <p>There are no names</p>;
return
<ul>{this.state.names.map(name=><li key={name}>{name}</li>)}ul>}
In the render method, we could then return it like
return
(<div>{this.renderNames()}</div> )}
A second way would be to use the logical operator :
render(){ return(<div>{this.state.names.length ===0 && 'no names'}</div>)}
Meaning,if the first half is true, then it will render what’s at the right of it:
this.state.names.length ===0
//if true, render the text of 'no names'.