June 2018 Update

Task/Empty-string/Factor/empty-string-1.factor

@@ -0,0 +1 @@
+"" empty? .

Task/Empty-string/Factor/empty-string-2.factor

@@ -0,0 +1,6 @@
+USE: locals
+[let
+    "" :> empty-string
+    empty-string empty? .
+    empty-string empty? not .
+]

Task/Empty-string/HolyC/empty-string.holyc

@@ -0,0 +1,12 @@
+/* assign an empty string */
+U8 *str = StrNew("");
+/* or */
+U8 *str = "";
+
+/* to test if string is empty */
+if (StrLen(str) == 0) { ... }
+/* or compare to a known empty string. "== 0" means strings are equal */
+if (StrCmp(str, "") == 0) { ... }
+
+/* to test if string is not empty */
+if (StrLen(str)) { ... }

Task/Empty-string/Red/empty-string.red

@@ -0,0 +1,6 @@
+Red []
+s: copy ""   ;; assign empty string
+?? s
+if empty? s [print "string is empty "]          ;; check if string is empty
+s: "abc"
+prin s unless empty? s  [print " not empty"]