55. Do not place a semicolon immediately following an if, for, or while condition

Do not use a semicolon after an if, for, or while condition because it typically indicates programmer error and can result in unexpected behavior.

Noncompliant Code Example

In this noncompliant code example, a semicolon is used immediately following an if condition:

if (a == b); {
  /* ... */
}

The statements in the apparent body of the if statement are always evaluated regardless of the result of the condition expression.

Compliant Solution

This compliant solution eliminates the semicolon and ensures that the body of the if statement is executed only when the condition expression is true:

if (a == b) {
  /* ... */
}

Applicability

Placing a semicolon immediately following an if, for, or while condition may result in unexpected behavior.

Bibliography