react add to array code example

Example 1: add new array at the back of react state

this.setState(prevState => ({
  myArray: [...prevState.myArray, "new value"]
}))

Example 2: functional component how to add to existing array react

const {useState, useCallback} = React;
function Example() {
    const [theArray, setTheArray] = useState([]);
    const addEntryClick = () => {
        setTheArray([...theArray, `Entry ${theArray.length}`]);
    };
    return [
        ,
        
{theArray.map(entry =>
          
{entry}
        )}
        
    ];
}

ReactDOM.render(
    ,
    document.getElementById("root")
);

Example 3: add new array at the back of react state

this.setState(prevState => ({
  myArray: [ {"name": "object"}, ...prevState.myArray]
}))