# V517. Potential logical error. The 'if (A) {...} else if (A) {...}' pattern was detected.

The analyzer detected a possible error in a construct consisting of conditional statements.

Consider the sample:

    if (a == 1)
      Foo1();
    else if (a == 2)
      Foo2();
    else if (a == 1)
      Foo3();

In this sample, the 'Foo3()' function will never get control. Most likely, we deal with a logical error and the correct code should look as follows:

    if (a == 1)
      Foo1();
    else if (a == 2)
      Foo2();
    else if (a == 3)
      Foo3()

In practice, such an error might look in the following way:

    if (radius < THRESH * 5)
      *yOut = THRESH * 10 / radius;
    else if (radius < THRESH * 5)
      *yOut = -3.0f / (THRESH * 5.0f) * (radius - THRESH * 5.0f) + 3.0f;
    else
       *yOut = 0.0f;

It is difficult to say how a correct comparison condition must look, but the error in this code is evident.

This diagnostic is classified as:

CWE-570 CERT-MSC01-C

You can look at examples of errors detected by the V517 diagnostic.