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The result of the / operator is the quotient from the division of the first arithmetic operand by the second arithmetic operand. Division operations are susceptible to divide-by-zero errors. Overflow can also occur during two's-complement signed integer division when the dividend is equal to the minimum (negative) value for the signed integer type and the divisor is equal to —1. ( See rule " NUM00-J . Detect or prevent integer overflow".)for more information. This noncompliant code example can result in a divide-by-zero error during the division of the signed operands num1 and num2.

This code can result in a divide-by-zero error during the division of the signed operands num1 and num2.

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This compliant solution tests the suspect division operation divisor to guarantee there is no possibility of divide-by-zero errors.

long num1, num2, result;

/* Initialize num1 and num2 */

if ((num2 == 0)) {
  // handle error
} else {
  result = num1 / num2;
}

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The % operator provides the remainder when two operands of integer type are divided. This noncompliant code example can result in a divide-by-zero error during the remainder operation on the signed operands num1 and num2.

long num1, num2, result;

/* Initialize num1 and num2 */

result = num1 % num2;

Compliant Solution (Modulo)

This compliant solution tests the suspect remainder operation divisor to guarantee there is no possibility of a divide-by-zero error.

long num1, num2, result;

/* Initialize num1 and num2 */

if ((num2 == 0)) {
  // handle error
} else {
  result = num1 % num2;
}

Risk Assessment

A divide-division or modulo by - zero can result in abnormal program termination and denial of service (DoS).

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Automated detection exists for C and C++ , but not for Java yet.

Related Guidelines

Bibliography

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