Comparisons as extremely useful in any programming language or platform, and Power Automate is not the exception. For example, the “greater” function helps us to have two values and compare them.
So let’s check it in more detail.
It follows a simple pattern.
- Integer, Float, or String to compare
- Integer, Float, or String for the comparison item.
Let’s start with a simple example:
greater(100,10) will return true
It also works with float numbers:
greater(12.3,12.2) will return true
Now let’s look at strings. They are much more complex to compare, and results may be strange in some areas. For example:
greater('b','a') returns true
It makes sense since we know that “a” comes before “b”, but so does:
greater('b','.a') returns true
Depending on how you look at it, it makes sense, or it’s wrong. Another example is with a string that contains a number.
greater('b','1') returns true
Depending on where you look, numbers come before or after when you sort alphabetically, so in this case, you know that numbers are not considered first. We can continue to find examples, but I think this proves my point. You can use it to understand if something is ordered, being a name is “after” another, but be careful and test your Flow. You may get unexpected results.
Let’s look at an array:
greater(createArray(1,2,3),createArray(4,5)) will return an error: Unable to process template language expressions in action 'Compose' inputs at line '1' and column '6323': 'The template language function 'greater' expects all of its parameters to be either integer or decimal numbers. Found invalid parameter types: 'Array'.'.
No arrays allowed. Finally, let’s try with boolean values:
greater(true,false) will return an error Unable to process template language expressions in action 'Compose_2' inputs at line '1' and column '6323': 'The template language function 'greater' expects all of its parameters to be either integer or decimal numbers. Found invalid parameter types: 'Boolean'.'.
The specification is apparent here. Boolean values are not comparable, but it’s nice to try and be sure.
Depending on the size of your string, your expression may return an error, even if it’s correct. Please note that the expressions have a max size of 8,192 characters. If you have an expression that is even bigger than 1000, I would strongly advise breaking it into smaller, manageable formulas.
Finally, as we’ve seen above, arrays, boolean values, and other objects outside strings, integers, and floats are not allowed. I can’t consider this as a limitation since it doesn’t make sense to compare them, but I wanted to stress it here since, in some cases, we can use variables or “Compose” action, for example, so that these values may exist.
Here are some things to keep in mind.
Use “debug” compose actions.
Since the comparison will return true or false, sometimes it’s tricky to understand how the calculation is done, depending on how complex the expression is. So I recommend using Compose actions to have the values that go “in” the function. This way, if the value doesn’t make sense, you can understand, based on the parameters, why it was calculated that way.
Please don’t use it on strings.
We are comparing if a string is “greater” than the other works, but it’s pretty hard to understand the outcome, as we’ve seen above. So even if the string contains a number, use the int function first and then compare. Otherwise, there’s no real reason to compare strings like this.
There’s no real reason to do it. Furthermore, if you try to nest “greater” functions, you’ll receive an error since boolean values are not comparable. So be very careful to avoid breaking Flows.
Back to the Power Automate Function Reference.