A real-life scenario where call, apply, and bind use

Sugriv Lodhi - Sep 2 - - Dev Community

A real-life scenario where call, apply, and bind are useful is when you have objects representing different users, and you want to reuse a method across these objects.

Scenario: Managing User Permissions
Imagine you have a system where different users have different
permissions, and you want to check if a user has a certain
permission.

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Function to Check Permissions
You have a function that checks if a user has a certain permission:

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Using call to Check Permissions Immediately

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Using apply to Check Permissions with Arguments as Array
If you had multiple permissions to check at once, you could use apply (though it's less common for single arguments):

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Using bind to Create a New Function for a Specific User
You might want to create a specific function for each user to check their permissions without having to pass the user object each time:

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Conclusion
*call, apply, and bind * are powerful methods in JavaScript that allow you to control the context (this value) in which a function is executed.

  • call: Immediately invokes a function with a specified this value and individual arguments, making it useful for applying methods across different objects in a straightforward manner.

  • apply: Similar to call, but accepts arguments as an array, making it more suitable when dealing with variable-length arguments.

  • bind: Creates a new function with a fixed this value, allowing you to easily reuse functions with a specific context in various parts of your application.

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