How to use a variable inside a Power Automate expression

Question

I'm trying to work with the setProperty function in order to edit a JSON body during the execution of a flow, here is the expression:

setProperty(X, 'Y','bla bla 123456789' )

while

• X is the json
• Y the property i want to modify
• 'bla bla 123456789' is the value

My question is: how can I replace '123456789' by a variable('ID') inside it, if I do the following thing

setProperty(X, 'Y','bla bla variable('ID')' )

It will take exactly what is written "variable('ID') and not the value of this variable !

any help ?

Answer 1

You have your variables('ID') within a string declaration so the variables object is not being accessed. You must concatenate the two separate strings ('bla bla' and variables('ID')); to do so, use the concat() function.

Your expression would look like this:

setProperty(X, 'Y', concat('bla bla ', variables('ID')))

---

If I am understanding the case you presented in the comments correctly, I believe you can still use the concat() function to accomplish this. You would need to concatenate the whole 'path' value with your variable ID.

The path value:

'/datasets/@{encodeURIComponent(encodeURIComponent(''.../sites/Support''))}/tables/@{encodeURIComponent(encodeURIComponent(''def533d7-8ede-4f29-b882-57d48a90c2d8''))}/onupdateditems'

would then become:

concat('/datasets/@{encodeURIComponent(encodeURIComponent(''.../sites/Support''))}/tables/@{encodeURIComponent(encodeURIComponent(''', variables('ID'), '''))}/onupdateditems')

Note that I am retaining the extra quotation marks to preserve the syntax of the original value.

The whole expression then becomes:

setProperty(body('Get_Flow')['properties']['definition'],'triggers', setProperty(body('Get_Flow')['properties']['definition']['triggers'], 'When_an_item_is_created_or_modified',setProperty(body('Get_Flow')['properties']['definition']['triggers']['When_an_item_is_created_or_modified'], 'inputs',setProperty(body('Get_Flow')['properties']['definition']['triggers']['When_an_item_is_created_or_modified']['inputs'], 'path',concat('/datasets/@{encodeURIComponent(encodeURIComponent(''.../sites/Support''))}/tables/@{encodeURIComponent(encodeURIComponent(''', variables('ID'), '''))}/onupdateditems')))))