Why Do Many People Avoid Using `goto`?

General
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Why Do Many People Avoid Using goto?

A recent discussion in a group sparked a debate about the goto statement. The conversation highlighted several reasons why many developers prefer to avoid using goto, despite its availability in many programming languages.

Key Points Against goto

  1. Code Readability and Maintainability: The primary concern is that goto can make code harder to read and maintain. Without proper indentation and labeling, goto can create a spaghetti-like structure, making it difficult for new developers to understand the flow of the program.

  2. Complexity in Debugging and Maintenance: Once a project grows, maintaining code that uses goto can become challenging. Debugging becomes more cumbersome, and the risk of introducing bugs increases significantly.

  3. Structured Programming Alternatives: Many modern programming practices advocate for structured programming techniques, such as loops (for, while, do-while) and conditional statements (if-else). These constructs are generally considered more intuitive and safer than goto.

  4. Programming Standards: Many coding standards explicitly prohibit the use of goto. For instance, in languages like C and Java, the break and continue statements are often preferred over goto because they are more controlled and easier to understand.

Arguments in Favor of goto

  1. Flexibility: Some argue that goto provides flexibility that structured constructs cannot. It allows for unconditional jumps, which can sometimes simplify complex logic.

  2. Historical Context: In the 1960s and 1970s, when structured programming was not as prevalent, goto was a common tool. However, as structured programming became more popular, the need for goto diminished.

  3. Language Design: Some programming languages, like Ada, acknowledge the criticisms of goto but still allow its use. However, Ada imposes strict syntax requirements, making goto usage more controlled and less prone to misuse.

Notable Criticisms

One of the most famous criticisms of goto comes from Edsger W. Dijkstra, who published a paper titled “Go To Statement Considered Harmful” in 1968. Dijkstra argued that unrestricted use of goto should be eliminated from high-level languages because it complicates the analysis and verification of program correctness, especially in cases involving loops.

Modern Usage and Best Practices

While goto is still supported in some languages, modern best practices generally discourage its use. Here are some guidelines:

  1. Use goto Only Within Functions: Avoid jumping between functions.
  2. Limit Scope: Use goto only within a small scope within a function.
  3. Avoid Complex Jumps: Ensure that goto does not cause the program to jump across significant blocks of code.
  4. Prevent Bidirectional Jumps: Avoid jumps that go in both directions, as this can lead to hard-to-follow code.

Example in Linux Kernel Code

Even in the Linux kernel, where goto is used, it is employed with caution. The kernel adheres to certain principles to ensure that the code remains readable and maintainable.

By understanding these principles and best practices, developers can make informed decisions about when and how to use goto in their projects.

This article was originally shared from Programmer’s Interactive Alliance (coder_online). If you have any questions or need further clarification, feel free to reach out.