Data commit

Task/Determine-if-a-string-is-numeric/PureBasic/determine-if-a-string-is-numeric.basic

@@ -0,0 +1,54 @@
+Procedure IsNumeric(InString.s, DecimalCharacter.c = '.')
+  #NotNumeric = #False
+  #IsNumeric = #True
+
+  InString = Trim(InString)
+  Protected IsDecimal, CaughtDecimal, CaughtE
+  Protected IsSignPresent, IsSignAllowed = #True, CountNumeric
+  Protected *CurrentChar.Character = @InString
+
+  While *CurrentChar\c
+    Select *CurrentChar\c
+      Case '0' To '9'
+        CountNumeric + 1
+        IsSignAllowed = #False
+      Case DecimalCharacter
+        If CaughtDecimal Or CaughtE Or CountNumeric = 0
+          ProcedureReturn #NotNumeric
+        EndIf
+
+        CountNumeric = 0
+        CaughtDecimal = #True
+        IsDecimal = #True
+      Case  '-', '+'
+        If IsSignPresent Or Not IsSignAllowed: ProcedureReturn #NotNumeric: EndIf
+        IsSignPresent = #True
+      Case 'E', 'e'
+        If CaughtE Or CountNumeric = 0
+          ProcedureReturn #NotNumeric
+        EndIf
+
+        CaughtE = #True
+        CountNumeric = 0
+        CaughtDecimal = #False
+        IsSignPresent = #False
+        IsSignAllowed = #True
+      Default
+        ProcedureReturn #NotNumeric
+    EndSelect
+    *CurrentChar + SizeOf(Character)
+  Wend
+
+  If CountNumeric = 0: ProcedureReturn #NotNumeric: EndIf
+  ProcedureReturn #IsNumeric
+EndProcedure
+
+If OpenConsole()
+  PrintN("'+3183.31151E+321' = " + Str(IsNumeric("+3183.31151E+321")))
+  PrintN("'-123456789' = " + Str(IsNumeric("-123456789")))
+  PrintN("'123.45.6789+' = " + Str(IsNumeric("123.45.6789+")))
+  PrintN("'-e' = " + Str(IsNumeric("-e")))
+  Print(#CRLF$ + #CRLF$ + "Press ENTER to exit")
+  Input()
+  CloseConsole()
+EndIf