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

Noncompliant Code Example

In this noncompliant code example, a semicolon is used on the same line as immediately following an if statement condition.

Code Block
bgColor#FFcccc
if (a == b); {
  /* ... */
}

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

Compliant Solution

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

Code Block
bgColor#ccccff
if (a == b) {
  /* ... */
}

Applicability

Placing a semicolon on the same line as immediately following an if, for, or while statement condition may result in unexpected behavior.

Related Guidelines

ISO/IEC TR 24772:2010

"Likely Incorrect Expression [KOA]"

Bibliography

[Hatton 1995]

Section 2.7.2, "Errors of omission and addition"

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