While Loops in Deluge

Last Updated: 2020-12-18

Introduction

If you are creating a workflow or custom function on a Zoho app, you may have noticed that Zoho's language, Deluge, does not have while loops. However, there is a way around this limitation.

Code

In Deluge, you can mimic the functionality of a while loop by creating a function that creates a list of a variable length. The code for this is:

 list Utility.getListOfLength(int length) 
{ 
   return if(length < 1,list(),"".leftpad(length - 1).toList("")); 
}

The function above will create a list with a variable number of empty elements, specified by the length parameter. If the parameter provided is less than 1, the list will be empty and non-iterable:

 info thisapp.Utility.getListOfLength(5).size(); // 5 
info thisapp.Utility.getListOfLength(0).size(); // 0 
info thisapp.Utility.getListOfLength(-5).size(); // 0

Usage

Basic

You can use the code above in conjunction with a for loop to get the functionality of a while loop:

 for each index i in thisapp.Utility.getListOfLength(100) 
{ 
   // for loop will iterate 100 times (specified by parameter) 
   // your code goes here 
}

Early Exits

In cases where you don't always need to iterate the specified amount of time, you can add a break; line within an if-block to exit the loop early:

 for each index i in thisapp.Utility.getListOfLength(100) 
{ 
   if(<BOOLEAN>) 
   { 
      break; 
   } 
   else 
   { 
      // your code goes here 
   } 
}

Note: with Deluge, a break must be placed inside the if block. If placed in the else block, you will receive the following error message: break statement cannot be used without loop.

Functionless

In applications outside of Zoho Creator, functions can't call other functions. The approach here is to inline the functionality:

 length = 10; 
for each index i in if(length < 1,list(),"".leftpad(length - 1).toList("")) 
{ 
   // your code goes here 
}

Closing

Though Zoho deluge doesn't offer native support for while loops, there are ways to make a for loops behave like one. While not usually needed, this is an important tool to know (and one that we often use).

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