Rule Definition
Any integer constant beginning with a “0” (zero) is treated as octal. Because of this, it is possible for a zero-prefixed constant that is intended to be a decimal number to be incorrectly entered as an octal number, contrary to developer expectations. Octal escape sequences can also be problematic because of the inadvertent introduction of a decimal digit (i.e. “8” or “9”) ends the octal escape and introduces another character. The integer constant zero (written as a single numeric digit), is strictly speaking an octal constant but is a permitted exception to this rule. Additionally, “\0” is the only permitted octal escape sequence.

Remediation
Use decimal integers rather than Octal constants

Violation Code Sample

code[ 3 ] = 052; // Non-compliant - equivalent to decimal 42
code[ 4 ] = 071; // Non-compliant - equivalent to decimal 57

code[ 5 ] = '\109'; // Non-compliant - implementation-defined,
// two character constant
code[ 6 ] = '\100'; // Non-compliant - set to 64.

Fixed Code Sample

code[ 1 ] =52; // Compliant - decimal 52
code[ 2 ] =71; // Compliant - decimal 71
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Exception
code[1] = 0

Standards Reference: MISRA C++ 2008, 2-13-2: Octal constants (other than zero) and octal escape sequences (other than "\0") shall not be used