Substitute Function Confusion

[NigelP]

Hi

Looking through the responses for the Substitute function.  It looks as if you have subsititute function in a "On Select" of a Button you must use Set(varfirstSubstitution,Substitute(<original string>,<string to replace>,<replacement string>)) and varfirstSubstitution holds the updated string.

If you use the substitute function elsewhere the Substitute(<original string>,<string to replace>,<replacement string>) and <original string > has been updated.

Am I correct ?

Thanks

Nigel

[rubin_boer · Accepted solution]

hi @NigelP the original string both cases should not change. if you have a variable "Some string" when you substitute the string whether onselect or in a label the variable will remain, substitute give you a new output. this is my understanding,

have la look at this

Set(_String,"This is a string") and assign the variable to a label

Substitute the string  Set(_SubstitudedString, Substitute(_String,"string","what")) and assing the variable to anopther label

the add both variable to a single label, you can see the _String variable remains unchanged.

Is you rexpereince different?

Hope this helps

[RandyHayes · Accepted solution]

@NigelP 

Substitute is a Function that returns a substituted string.  It does not alter the original string.

If you use substitute on a non-behavioral property (for example, the Text property of a label), it will use the results of the function.

Example - a Label Text property:  Substitute("My Dog is Brown", "Dog", "Horse") will display My Horse is Brown in the label.

If you use Substitute in a behavioral action (an OnSelect for example), then this implies you are going to do something with it.

Example:   Set(myVar,  Substitute("My Dog is Brown", "Dog", "Horse") )  will give you a variable with  My Horse is Brown in it.

Also worth noting, substitute can be chained (as with almost all functions in PowerApps).  So the following in a Label Text property:

    Substitute(Substitute("My Dog is Brown", "Dog", "Horse"), "Brown", "White")

would display My Horse is White

I hope this is helpful for you.