Adds a specified prefix to each element within a list.
Usage
When using, for example, the "listcontains" function on the number 1, this will pull out all instances of that number within a list (i.e. 1, 21, 31 will pull out 3 items). By prefixing each element you can successfully pull out just the required item. An example is shown below where we just want to pull out the number 1: