Execution Contexts, Hoisting, Scopes, and Closures

Execution Contexts, Hoisting, Scopes, and Closures are fundamental concepts in JavaScript programming language. Screenshot from https://ui.dev/ course and it were called “Tyler”

• Context refers to the **this** keyword, which is always the first parameter that can be received by a function with the **bind** method. If it is not received, it will look for it in its parent, until it reaches the **window** object. If it cannot be found, it will throw an error.
• Hoisting is the process of declaring a variable before it is used in the code.
• Scope refers to the range of accessibility of a function or a variable.

Closures

Closures are created when a function is defined inside another function. The inner function creates a closure with its parent function. When a program starts, the **window** object is created, along with the **this** keyword that references the **window**, and the functions and variables that exist. When a function is called, a function context is created. Instead of creating the **window** object, the **arguments** object is created. If a function or an arrow function is used, a different context is created. Functions have a scope, and a function inside another function is a closure.

• Context refers to the **this** keyword, which is the first parameter that can be received by a function. If it is not received, it will look for it in its parent, until it reaches the **window** object. If it cannot be found, it will throw an error.
• Hoisting is the process of declaring a variable before it is used.
• Scope is the range of accessibility of a function or a variable.
• Closures occur when a function is created inside another function. The inner function creates a closure with its parent function. When a program is initiated, the **window** object is created, along with the **this** keyword that references the **window**, and the functions and variables that exist. When a function is called, a function context is created. Instead of creating the **window** object, the **arguments** object is created. If a function or an arrow function is used, a different context is created. Functions have a scope and a function inside another function is a closure.