We often compare one range values with another range to check for duplicates. But how to check if one range values exist in another range in Excel? We will learn in this article how to check if a range contains a value not in another range in Excel.
Figure 1. Check If a Range Contains a Value Not in Another Range
The generic formula syntax is;
In this formula, we use the SUMPRODUCT function along with MATCH and ISNA function. This formula checks if range one contains at least one or more values that are not part of another range and returns TRUE, else it returns FALSE.
Figure 2. Formula Syntax
Suppose we have two lists of students’ roll numbers and we want to check if List A contains any values (one or more values) that are not in List B. Hence, the formula compares List A (range B2: B11) with List B (range C2: C11) and returns TRUE if List A contains at least one or more values not in List B, such as;
Figure 3. The Formula Result
How Formula Works
The MATCH function returns the relative positions of range B2: B11 values that exactly match in range C2: C11, and returns the #NA error value(s) where range B2: B11 values are not found in range C2: C11 as an array. Select the MATCH part of the formula in the formula bar and press F9 to view the resulting array.
Figure 4. Resulting Array of the MATCH Function
The ISNA function checks for the #NA error values and returns TRUE, else returns FALSE. Hence, it converts the array returned by the MATCH function into an array of TRUE and FALSE logical values, such as;
Figure 5. The array of Logical Values Return by the ISNA Function
The double dash (–) symbol converts the TRUE and FALSE logical values into an array of 1s and 0s. The SUMPRODUCT function sums this final array of 1s and 0s and compares the result with 0 and returns TRUE if the sum of values is greater than 0.
Figure 6. Final Array of 1s and 0s
Figure 7. Final Result of the Formula