What is the this keyword in JavaScript?

The this keyword refers to the object that is executing the current function. Its value depends on how the function is called:

1. Global Context:

console.log(this); // Window object (browser) or global (Node.js)

2. Object Method:

const obj = {
  name: "John",
  greet() {
    console.log(this.name); // "John"
  }
};

3. Constructor Function:

function Person(name) {
  this.name = name; // refers to new instance
}

4. Arrow Functions:

const obj = {
  name: "John",
  greet: () => {
    console.log(this.name); // undefined (inherits from enclosing scope)
  }
};

5. Explicit Binding:

function greet() {
  console.log(this.name);
}
greet.call({name: "John"}); // "John"