Data commit

Task/String-matching/VBA/string-matching.vba

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+Public Sub string_matching()
+    word = "the"                                        '-- (also try this with "th"/"he")
+    sentence = "the last thing the man said was the"
+    '--       sentence = "thelastthingthemansaidwasthe" '-- (practically the same results)
+
+    '-- A common, but potentially inefficient idiom for checking for a substring at the start is:
+    If InStr(1, sentence, word) = 1 Then
+        Debug.Print "yes(1)"
+    End If
+    '-- A more efficient method is to test the appropriate slice
+    If Len(sentence) >= Len(word) _
+        And Mid(sentence, 1, Len(word)) = word Then
+        Debug.Print "yes(2)"
+    End If
+    '-- Which is almost identical to checking for a word at the end
+    If Len(sentence) >= Len(word) _
+        And Mid(sentence, Len(sentence) - Len(word) + 1, Len(word)) = word Then
+        Debug.Print "yes(3)"
+    End If
+    '-- Or sometimes you will see this, a tiny bit more efficient:
+    If Len(sentence) >= Len(word) _
+    And InStr(Len(sentence) - Len(word) + 1, sentence, word) Then
+        Debug.Print "yes(4)"
+    End If
+    '-- Finding all occurences is a snap:
+    r = InStr(1, sentence, word)
+    Do While r <> 0
+        Debug.Print r
+        r = InStr(r + 1, sentence, word)
+    Loop
+End Sub