How to add multiple elements to an array under the same id?

Question

React

For example: given a form with "input' and "textarea", how can I put their values ​​in an array under the same id? And is it possible to use "input" as id?

addItem = (e) => {
        e.preventDefault();
        const{ inputText, textareaText } = this.state;
        this.setState({
            items: [],
            inputText: '',
            textareaText: '',

        })
        this.state.items.push( inputText, textareaText );
        this.setState ({ items: this.state.items });
    }
    render(){
        const { inputText, textareaText } = this.state;
        const list = this.state.items.map(({ id, value, title }) => {
            return <li key={id} value={ value }>{ title }</li>;
        })