expected ';' before '...'

The expected ';' before '...' error means the compiler expected a semicolon where it found something else. In C/C++, semicolons terminate most statements.

What It Means

The compiler’s parser reached a token it did not expect. The previous statement likely lacks its terminating semicolon. The error location can be misleading — the actual problem is often on the line above.

Why It Happens

• Missing semicolon at the end of a statement
• Class, struct, or enum definition missing a semicolon after the closing brace
• Missing semicolon after a struct or class definition
• A macro or typedef without a semicolon
• Copy-paste errors that break statement boundaries

How to Fix It

Step 1: Check the line before the error

#include <iostream>

int main() {
    int a = 5  // missing semicolon!
    int b = 10;
    std::cout << a + b << std::endl;
    return 0;
}

g++ semicolon.cpp -o semicolon
# error: expected ';' before 'b'

Fix: Add ; after int a = 5.

Step 2: Add semicolon after class/struct definition

#include <iostream>

struct Point {
    int x;
    int y;
}  // missing semicolon!

int main() {
    Point p;
    return 0;
}

// fixed
struct Point {
    int x;
    int y;
};

Step 3: Fix missing semicolon in typedef

typedef struct {
    int id;
    char name[50];
} Employee  // missing semicolon!

// fixed
typedef struct {
    int id;
    char name[50];
} Employee;

Step 4: Check for missing semicolons in macros

#define SQUARE(x) ((x) * (x))  // no semicolon in macro definition

int main() {
    int result = SQUARE(5)  // missing semicolon!
    return 0;
}

// fixed
int main() {
    int result = SQUARE(5);
    return 0;
}

Step 5: Use compiler error location hints

The compiler often points to the token that confused it:

error: expected ';' before 'return'
   12 |     return 0;
      |     ^~~~~~

The actual missing semicolon is near line 11, but the compiler reports the error when it hits return on line 12. Always look at the line before the error location first.