Just another update

Task/Empty-string/00DESCRIPTION

@@ -1,4 +1,5 @@
-Languages may have features for dealing specifically with empty strings (those containing no characters).
+Languages may have features for dealing specifically with empty strings
+(those containing no characters).
 
 The task is to:
 
@@ -7,4 +8,4 @@ The task is to:
 * Demonstrate how to check that a string is empty.
 * Demonstrate how to check that a string is not empty.
 
-[[Category:String manipulation]]
+[[Category:String manipulation]] [[Category:Simple]]

Task/Empty-string/Elixir/empty-string.elixir

@@ -0,0 +1,12 @@
+empty_string = ""
+not_empty_string = "a"
+
+empty_string == ""
+# => true
+String.length(empty_string) == 0
+# => true
+
+not_empty_string == ""
+# => false
+String.length(not_empty_string) == 0
+# => false

Task/Empty-string/Go/empty-string.go

@@ -1,8 +1,14 @@
-// assign empty string to a variable
+// define and initialize an empty string
+var s string
+s2 := ""
+
+// assign an empty string to a variable
 s = ""
 
-// check that string is empty
+// check that a string is empty, any of:
 s == ""
+len(s) == 0
 
-// check that string is not empty
-s > ""
+// check that a string is not empty, any of:
+s != ""
+len(s) != 0 // or > 0

Task/Empty-string/JavaScript/empty-string-1.js

@@ -0,0 +1,2 @@
+var s = "";
+var s = new String();

Task/Empty-string/JavaScript/empty-string-2.js

@@ -0,0 +1,4 @@
+s == ""
+s.length == 0
+!s
+!Boolean(s)

Task/Empty-string/JavaScript/empty-string-3.js

@@ -0,0 +1,4 @@
+s != ""
+s.length != 0
+s.length > 0
+Boolean(s)

Task/Empty-string/Maple/empty-string.maple

@@ -0,0 +1,3 @@
+s := ""; # Create an empty string
+evalb(s = ""); # test if the string is empty
+evalb(s <> ""); # test if the string is not empty

Task/Empty-string/Prolog/empty-string.pro

@@ -0,0 +1,4 @@
+assign_empty_string(Variable) :- Variable = "".
+
+is_empty_string(String)  :- String ==  "".
+not_empty_string(String) :- String \== "".

Task/Empty-string/Smalltalk/empty-string.st

@@ -0,0 +1,8 @@
+"Assign empty string to a variable"
+str := ''.
+
+"Check that string is empty"
+str isEmpty.
+
+"Check that string is not empty"
+str isEmpty not.

Task/Empty-string/Standard-ML/empty-string.ml

@@ -0,0 +1,6 @@
+(* Assign empty string to a variable *)
+val s = ""
+(* Check that a string is empty*)
+s = ""
+(* Check that a string is nonempty *)
+s <> ""