Understand Call, Apply And Bind In JavaScript
In JavaScript, “apply”, “call”, and “bind” are methods used to manipulate the value of this within a function and to pass arguments to a function. They are commonly used when dealing with function invocation and context management. Let’s explore each of these methods:
1. Apply:
The “apply” method allows you to invoke a function and specify both the value of this and an array or array-like object of arguments to be passed to the function.
2. Call:
Similar to “apply” the “call” method allows you to invoke a function and specify the value of “this”, followed by a list of arguments.
3. Bind:
The “bind” method returns a new function that, when invoked, has its “this” value set to a specified value. It also allows you to “bind” arguments to the function, effectively creating a partially applied function.
In summary:
- apply takes two arguments: the value of “this” and an array of arguments.
- call takes multiple arguments: the value of “this” followed by individual arguments.
- bind returns a new function with a fixed value of “this”and optionally pre-bound arguments.
These methods are especially useful when you want to control the context in which a function is executed or when you want to reuse functions with different context and arguments. Keep in mind that arrow functions do not have their own this value, so apply, call, and bind behave differently when used with them.