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--- 4rpl:commands:refexists [2021/01/13 17:46] – virgilw
+++ 4rpl:commands:refexists [2021/01/15 07:50] (current) – changed dynamic to reference for consistency Sanian
@@ Line 1: / Line 1: @@
-~~NOTOC~~
+ <=[[4rpl:start| Index]]
-<=[[4rpl:start| Index]]
+====== Variable Exists (by reference) ======
+===== Syntax =====
-=== Syntax ===
 -?!
-=== Description ===
+===== Description =====
-Takes a string from the stack and uses it as a variable name.
-Checks to see if the variable exists (has been assigned).
+Takes a string from the stack and uses it as a variable name. If the variable exists (has been assigned),1 (true) is pushed to the stack, otherwise 0 (false).
-If so, 1 is pushed to the stack else 0.
+===== Examples =====
-=== Examples ===
 <code 4rpl>
-# Build a string by concatenating "xy" and "z".
+"Santa isn't r-" ->secret
-"xy" "z" concat
--?! trace
-</code>
+if ("secret" -?!)
+    "I know a secret" Trace
+else
+    "I know no secrets" Trace
+endif
+</code>
+~~NOTOC~~

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