~~NOTOC~~
<=[[4rpl:start| Index]]

====== dup ======
dup

===== Description =====
Duplicates the item currently on the stack without removing the original item.

:WARNING: If you do the following, or something similar: ''CreateList dup ->list1 ->list2'' This will create a **shallow** copy of the list, so that any changes made to them will affect both. Use [[DeepCopy]].
===== Examples =====
<code 4rpl>
trace2(42 dup) #prints '42 42'
</code>
<=[[4rpl:start| Index]]