Can java or appscript test whether a string occurs once in a text field?

[pbustin]

I set a form action to show Field B if a text Field A contains a string.  I would like to hide Field B if the string only occurs once in Field A.  Can javascript or appscript accomplish this?

[RAMASAMY BHARATHARUN]

Yes, definitely you can do such validations in java script / App script.

[pbustin]

Thank you.  That's encouraging.  I wonder what would that look like in javascript and appscript.

[RAMASAMY BHARATHARUN]

You need to spilt the text field value by your string and check the length of your string array after split to take decision.

[pbustin]

Thanks! And what would that look like?

[PM Thompson · Accepted solution]

this will determine if Field A has 1 occurrence of "the string" (in any case) and hide Field B if so, otherwise it will show field B. 

var matches = GetFieldValue("Field A").match(/the string/gi) ;
if ( matches !== null && matches.length === 1) {
   HideField("B");
} else {
   ShowField("B");
}

[pbustin]

Thank you.

Would the 'if' statement that follows test for field "B" as empty?

[pbustin]

I suppose I could set another variable instead of hiding or showing field "B"?