javascript - React: How to build a string with state values?

Question

This question already has answers here: question from:https://stackoverflow.com/questions/65848140/react-how-to-build-a-string-with-state-values

Answer 1

there is need to fix this reference, try this code:

import React from "react";
import "bootstrap/dist/css/bootstrap.min.css"

class Unternehmenseinstellungen extends React.Component {
    constructor(props) {
        super(props);
        this.state = {
            uname: ""
        };
        this.handleUName = this.handleUName.bind(this);
        this.unternehmensenden = this.unternehmensenden.bind(this);
    }
    
    handleUName(e) {
        this.setState({uname: e.target.value});
    }
    
    unternehmensenden() {
        if (document.getElementById("uname").value === "") {
            alert("Please fill all fields");
        }
        else {
            var apiEndpoint = "http://localhost:8080/erstelleUnternehmen?uname=" + this.state.uname;
            alert(apiEndpoint)

        }
    }
    
    render() {
        return (
        <div>
            <div>
              <input placeholder="e.g. Bike company"
                                       value={this.state.uname}
                                       onChange={this.handleUName}
                                       style={{...}}
                                       type="text" id="uname" required/>
                        
            </div>

            <button
                style={{...}}
                className="btn btn-pill btn-dark" onClick={this.unternehmensenden}>Show my state                              
            </button>
            <div>
              <h3>State-Test:</h3>
              <p>Name: {this.state.uname}</p>
            </div>
        </div>
        );
    }
}