Which Programming Languages Use Semicolons? We Counted 4,437 of Them

1. Semicolons in Every Major Language

Languages fall into four groups: semicolons required, optional, not used, or meaningful. Here is where the common ones sit.

2. How Many Semicolons Each Language Uses

We counted every semicolon in 1,340 snippets from our practice library, after removing comments and the contents of strings so that only semicolons in code were counted.

C leads by a distance. One character in every 26 is a semicolon, and it is the most common symbol in C, ahead of the parentheses. Part of that is the for loop: 38 loops in our C snippets use the classic three-part header, which puts two semicolons in every one.

C++ and TypeScript have the semicolon in second place, behind the colon. In C++ the colon comes from std::; in TypeScript it comes from type annotations, and 61 TypeScript lines are typed members or fields that end in a semicolon, such as name: string;.

3. Why Do Programming Languages Use Semicolons?

A semicolon tells the compiler exactly where one statement ends and the next begins. Without a marker, a parser has to guess whether a line break ends the statement or whether the expression continues on the next line.

The habit is old. ALGOL 60 used semicolons to separate statements, Pascal kept that, and C made the semicolon a terminator that ends every statement. Because C, C++, Java, C#, JavaScript and PHP all borrowed C's syntax, most of the world's code inherited the rule. A terminator has a practical advantage: the code does not depend on line breaks, so you can split a long expression across lines, or put two statements on one, without changing its meaning.

Newer languages mostly decided the line break was enough. Python, Ruby, Swift and Kotlin end a statement at the end of the line unless the expression is clearly unfinished. Go is a middle path: the grammar still uses semicolons, but the compiler inserts them automatically at line ends, so Go programmers almost never type one.

4. Do You Need Semicolons in JavaScript?

Strictly, no. JavaScript has automatic semicolon insertion (ASI): when a line break would otherwise produce invalid code, the parser inserts a semicolon for you. Most code without semicolons runs exactly as intended. The danger is the cases where the code is still valid without a break, so nothing is inserted:

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  A line that starts with ( or [. const a = b followed by a line starting with ( is read as calling b as a function.

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  A line that starts with a backtick. The previous expression is treated as a tag for the template literal.

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  return on its own line. A semicolon is inserted straight after return, so the function returns undefined and the value on the next line is never reached.

Teams settle this with a style rule rather than memory. Prettier adds semicolons by default, as does the Airbnb style guide; StandardJS leaves them out and relies on lint rules to catch the risky lines. Either works if a tool enforces it.

Our JavaScript and TypeScript snippets are written with semicolons throughout: all 150 JavaScript snippets contain them. The only lines before a closing brace that end without one are object properties and enum members, which take a comma or nothing at all.

5. Rust: The Semicolon That Changes the Value

Rust treats almost everything as an expression, and the semicolon is what turns an expression into a statement that discards its value. The last expression in a block, written without a semicolon, becomes the value of the block. That is how most Rust functions return:

fn area(w: f64, h: f64) -> f64 { w * h }

Add a semicolon after w * h and the block returns (), the empty value, so the compiler reports mismatched types and suggests removing the semicolon. It is one of the first errors every Rust learner meets.

Our data shows the difference clearly. In C, C++, Java and PHP, 99% to 100% of the lines just before a closing brace end with a semicolon. In Rust it is 62%: 68 of 181 blocks end with a bare expression such as x * y, Ok(x / y) or values.iter().sum(), which is the value the block hands back.

6. Other Places Semicolons Appear

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  For loops. for (int i = 0; i < n; i++) uses two semicolons to separate its three parts, in C, C++, Java, JavaScript, PHP and even Go. for (;;) is an infinite loop.

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  After a closing brace in C and C++. Struct, enum and class definitions end with };, and a do-while loop ends with while (...);. Function bodies do not, which is a classic beginner mix-up. Our C snippets have 17 lines ending in };, from type definitions and initializer lists.

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  CSS. Every declaration ends with one, as in color: red;. 233 of the 235 semicolons in our HTML & CSS snippets are CSS; the other two end HTML entities such as &.

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  Python one-liners. Python allows x = 1; y = 2 on one line, but PEP 8 discourages putting several statements on a line, and our Python snippets never do.

7. Typing the Semicolon

On a QWERTY keyboard the semicolon is the home key of the right little finger, so you can type it without moving your hand. That is lucky, because in C-style languages it is one of the most typed keys of all. In our C snippets the semicolon is 18% of everything the right little finger types.

The common mistakes are rhythm mistakes: forgetting it at the end of a line, or adding one where it does not belong, after a function body or the condition of an if. Many editors now add the semicolon automatically, but typing it as part of the line, rather than as an afterthought, keeps your hands on the home row. Our keystroke analysis shows how much of a programmer's typing lands on that finger.

8. Method and Limits

We analysed 1,340 snippets from TurboType's practice tracks: 150 each in JavaScript, TypeScript, Java, C, C++, PHP, Rust and HTML & CSS, and 140 in Python (ten object-oriented Python snippets were excluded). Comments and the contents of strings were removed before counting. Per-line figures count non-empty lines. The closing-brace test looks at the last line before a line that starts with }, ignoring lines that end in {, } or a comma.

Limits: practice snippets are short, so for loops and declarations are over-represented compared with long functions in production code. The language rules in the first table hold everywhere; the counts describe our sample.

9. Frequently Asked Questions