js bind change

function greet(greeting, punctuation) {
    return greeting + ', ' + this.name + punctuation;
}

const person = { name: 'Alice' };
const greetPerson = greet.bind(person, 'Hello');
console.log(greetPerson('!')); // 输出: Hello, Alice!

class MyComponent {
    constructor() {
        this.value = '';
    }

    handleChange(event) {
        this.value = event.target.value;
    }

    render() {
        const inputElement = document.createElement('input');
        inputElement.addEventListener('change', this.handleChange); // 这里的 this 不会指向 MyComponent 实例
        document.body.appendChild(inputElement);
    }
}

class MyComponent {
    constructor() {
        this.value = '';
        this.handleChange = this.handleChange.bind(this); // 绑定 this
    }

    handleChange(event) {
        this.value = event.target.value;
    }

    render() {
        const inputElement = document.createElement('input');
        inputElement.addEventListener('change', this.handleChange);
        document.body.appendChild(inputElement);
    }
}

function logMessage(message, level) {
    console.log(`[${level}] ${message}`);
}

const logError = logMessage.bind(null, 'An error occurred', 'ERROR');
logError(); // 输出: [ERROR] An error occurred