Pointers in C Programming - Lay Man&#s Analogy

Understanding C language pointers: a simple analogy

This article will explain the concept of pointers in C language in an easy-to-understand way, which even experienced programmers may benefit from. We'll use a real-life example to explain what pointers mean and dispel common misunderstandings.

The metaphor of house and address

Each house has an address and also has its own description such as colour, architectural style and type. Even if it is a vacant lot, an address is usually reserved.

Suppose John Doe wants to know about your house, you can give him the address (a more efficient method), or you can describe the characteristics of the house. But there's a problem with just describing a house: other houses may look similar to yours, making it difficult for John Doe to find your house. And with the address, he can accurately find your house. Remember this simple metaphor.

Analog pointer

The street represents the C language environment, the house represents the value of the variable (the variable is like a container), and the address is stored in the pointer. There can only be one pointer per value, just like there is only one address per house (even adjacent houses have different addresses). In programming, we avoid waste, so one pointer corresponds to one address.

However, there can be multiple houses of the same type on the same street, and similarly, variables at different addresses can have the same data type. Each variable has its own unique memory address unless explicitly made to reference the same address.

Using pointers in C is more efficient, just like providing an exact address is more efficient than describing a house (especially if there are many houses on a street). This is one of the reasons why C language is efficient. Linus Torvalds, the designer of the Linux operating system, once said:

I have never seen a more efficient operating system or machine programming language than C.

Some C language code

The following figure shows how to write pointers in C language:

• *ptr is a pointer
• &var is the address
• *ptr is like a piece of paper with the exact address written on it (&var is the memory address)
• **ptr is a pointer to a pointer, which can be understood as: you need to put the paper with the address on it somewhere, and you need to know the exact location of the paper, so it also has its own location or address.
• int means we are dealing with numbers (integers).

While this is a simplified analogy, even experienced programmers will find it a good explanation to get started. Hope this helps you understand C pointers.

Fun fact: C language is one of the cornerstones of NASA flight software.

The above is the detailed content of Pointers in C Programming - Lay Man&#s Analogy. For more information, please follow other related articles on the PHP Chinese website!