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Do not use a semicolon on the same line as after an if, for, or while statement condition because this it 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 statement are always evaluated regardless of the result of the condition expression.

Compliant Solution

It is likely, in this example, that the semicolon was accidentally inserted.This compliant solution eliminates the semicolon and ensures that the body of the if statement is executed only when the condition expression is true:

Code Block
bgColor#ccccff

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

Related Guidelines

Applicability

Placing a semicolon immediately following CERT C Secure Coding Standard: EXP15-C. Do not place a semicolon on the same line as an if, for, or while statement

Bibliography

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condition may result in unexpected behavior.

Automated Detection

ToolVersionCheckerDescription
PVS-Studio

Include Page
PVS-Studio_V
PVS-Studio_V

V6063
SonarQube
Include Page
SonarQube_V
SonarQube_V
EmptyStatementUsageCheck


Bibliography

[Hatton 1995]

§2.7.2,

...

"Errors

...

of Omission and Addition"


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Image Added Image Added Image Added omission and addition"FIO14-J. Use an int to capture the return value of functions that read a character or byte      12. Input Output (FIO)      13. Input Validation and Data Sanitization (IDS)