Flow - How to remove duplicate email addresses from array variable?

[sienna28]

In my flow, I have read email addresses from a list into an array variable.

I have some duplicate email addresses in there and I would like to keep one version only.

How can I remove duplicates and build up a string of email addresses, seperated by semicolons,  to use in the To: field of the email to be sent? 

So address1; address2;address3;address4 etc

Thank you

[xyzzyx666 · Accepted solution]

Hi @sienna28,

Could you please share a screenshot of your flow’s configuration?

You can try to use Union to remove the duplicate email address and use join with(;)to change "," to ";".

I have tested as next.

Step1: create one SP list(the list has two same eamil adress to test).

Step2:Configure the flow: Use Union and Join

Step3:check it and then test

Hope this can be helpful.

BR,

xyz

[Anonymous · Accepted solution]

Thanks for your help in this thread @xyzzyx666! 

@sienna28 thanks for your post - can you review the information provided and let us know if it answers your question?

@Anonymous

[Anonymous]

Hi,

Could you please share what the actions are? The screenshots provided are very hard to read.

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@Anonymous wrote:

Thanks for your help in this thread @xyzzyx666! 

@sienna28 thanks for your post - can you review the information provided and let us know if it answers your question?

@Anonymous

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[Jasong911]

hi, 

this solution doesn't show what you append to the array variable? 

also doesn't show the exact expression you used for Compose/Join?

could you please clarify?

[DTreg1]

@Jasong911 

Did you ever happen to figure out the rest of the expressions?

[rchapman]

You can just perform the union against the same array to remove duplicates.

In the compose expression:

union(variables('emails'), variables('emails'))

to store the result back into an array just use a Set Variable and type "Outputs" in the dynamic content search option and locate the Outputs specific to the naming of the compose expression that you put the union code in.

[ManiLive]

A faster way to remove duplicates is to union the input array with an empty array.  This saves a lot of time with larger sets.
Initialize an empty array using Compose and use another Compose to union the input array with the empty array.

[Beat]

@xyzzyx666 the combination of union() and join() does the trick. Ingeniously simple, thank you!

Whatever I tried returned escaped double quotes as in 
'emailMessage/To' is required to be of type 'String/email'. The runtime value '"[\"username@company.com;\"]"' to be converted doesn't have the expected format 'string/email'.

I didn't need a compose action, actually:

[Beat]

Makes most sense! I shall definitely try that next time. Now I have just a couple of dozens of email addresses, no worries.