To Use or Not to Use Semicolons in JavaScript: Mandatory or Optional?

Semicolons in JavaScript: Mandatory or Optional?

Often, JavaScript interpreters will automatically insert semicolons when you omit them. However, the question arises: should you leave them out in the first place?

Understanding Semicolon Insertion

The Mozilla site provides guidelines for semicolon insertion. The crux of the rule is that if a grammatically valid series of tokens (up to token n) becomes invalid after the next token (token n 1), a semicolon will be inserted if there's a line break between token n and token n 1.

While the rule provides a solid explanation for most scenarios, it may not cover all cases, including the example provided by @Dreas. Comprehensive documentation on the complete rules for semicolon insertion would be helpful to clarify such anomalies.

Recommendation

Despite the automatic insertion feature, it is highly recommended to use semicolons after every statement in JavaScript. This practice ensures code readability, consistency, and compatibility across different JavaScript platforms and interpreters.

By adhering to this best practice, you minimize the risk of unintended program behavior due to the omission of semicolons or unexpected semicolon insertion. Semicolons serve as clear statement terminators, making code more organized and easier to maintain.

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