# V695\. Range intersections are possible within conditional expressions\.

The analyzer has detected a potential error in a condition\. The program must perform different actions depending on which range of values a certain variable meets\.

For this purpose, the following construct is used in the code:

```cpp
if ( MIN_A < X && X < MAX_A ) {
  ....
} else if ( MIN_B < X && X < MAX_B ) {
  ....
}
```

The analyzer generates the warning when the ranges checked in conditions overlap\. For example:

```cpp
if ( 0 <= X && X < 10)
  FooA();
else if ( 10 <= X && X < 20)
  FooB();
else if ( 20 <= X && X < 300)
  FooC();
else if ( 30 <= X && X < 40)
  FooD();
```

The code contains a typo\. The programmer's fingers faltered at some moment and he wrote "20 <\= X && X < 300" instead of "20 <\= X && X < 30" by mistake\. If the X variable stores, for example, the value 35, it will be the function FooC\(\) that will be called instead of FooD\(\)\.

The fixed code:

```cpp
if ( 0 <= X && X < 10)
  FooA();
else if ( 10 <= X && X < 20)
  FooB();
else if ( 20 <= X && X < 30)
  FooC();
else if ( 30 <= X && X < 40)
  FooD();
```



Here is another example:

```cpp
const int nv_ab = 5;
const int nv_bc = 10;
const int nv_re = 15;
const int nv_we = 20;
const int nv_tw = 25;
const int nv_ww = 30;
....
if (n < nv_ab) { AB(); }
else if (n < nv_bc) { BC(); }
else if (n < nv_re) { RE(); }
else if (n < nv_tw) { TW(); }   // <=
else if (n < nv_we) { WE(); }   // <=
else if (n < nv_ww) { WW(); }
```

Depending on the value of the 'n' variable, different actions are performed\. Poor variable naming may confuse a programmer \- and so it did in this example\. The 'n' variable should have been compared to 'nv\_we' first and only then to 'nv\_tw'\.

To make the mistake clear, let's substitute the values of the constants into the code:

```cpp
if (n < 5) { AB(); }
else if (n < 10) { BC(); }
else if (n < 15) { RE(); }
else if (n < 25) { TW(); }
else if (n < 20) { WE(); } // Condition is always false
else if (n < 30) { WW(); }
```

The fixed code:

```cpp
if (n < nv_ab) { AB(); }
else if (n < nv_bc) { BC(); }
else if (n < nv_re) { RE(); }
else if (n < nv_we) { WE(); }    // <=
else if (n < nv_tw) { TW(); }    // <=
else if (n < nv_ww) { WW(); }
```