What knowledge does a good closure require?

The knowledge required is: 1. Understand the definition and calling method of functions, as well as the concept of function scope; 2. Understanding the relationship between internal functions and external functions is an important prerequisite for understanding closures; 3 , Understand how lexical scope affects variable access and life cycle of functions; 4. Understanding the life cycle of variables is important for understanding the memory management and performance optimization of closures; 5. Understand the common application scenarios of closures, such as encapsulating private Variables, implementing function currying, implementing modularization, etc.; 6. Understand how to use closures correctly, avoid common pitfalls, and optimize the performance of closures.

Operating system for this tutorial: Windows 10 system, Dell G3 computer.

To understand and write closures well, you need to have the following knowledge points:

• Function and scope: Understand the definition and calling method of functions, as well as functions The concept of scope. Closures are implemented based on the characteristics of function scope.

• Inner and outer functions: A closure is composed of an inner function and a reference to its outer environment. Understanding the relationship between internal functions and external functions is an important prerequisite for understanding closures.

• Lexical scope: Closures are based on lexical scope, which is the scope in which the function is defined. To understand closures, you need to understand how lexical scope affects variable access and lifetime of functions.

• The life cycle of variables: The inner function in the closure can access the variables of the outer function, and the life cycle of these variables will be extended until the inner function is no longer referenced. Understanding the lifetime of variables is important to understanding memory management and performance optimization of closures.

• Application scenarios of closures: Understand the common application scenarios of closures, such as encapsulating private variables, implementing function currying, implementing modularization, etc. Familiarity with these use cases can help you better understand the practical uses of closures.

• Memory management and performance optimization: Closures can cause memory leaks and performance issues, so it is important to understand how to use closures correctly, avoid common pitfalls, and optimize closure performance of.

The above are some basic knowledge required to understand and write closures well. Through in-depth study and practice, you can better master the concepts, principles, and applications of closures.

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