countof()
Applies to: ✅ Microsoft Fabric ✅ Azure Data Explorer ✅ Azure Monitor ✅ Microsoft Sentinel
Counts occurrences of a substring in a string. Plain string matches may overlap; regex matches don't.
Syntax
countof(source, search [, kind])
Learn more about syntax conventions.
Parameters
| Name | Type | Required | Description |
|---|---|---|---|
| source | string |
✔️ | The value to search. |
| search | string |
✔️ | The value or regular expression to match inside source. |
| kind | string |
The value normal or regex. The default is normal. |
Returns
The number of times that the search value can be matched in the source string. Plain string matches may overlap; regex matches don't.
Examples
| Function call | Result |
|---|---|
countof("aaa", "a") |
3 |
countof("aaaa", "aa") |
3 (not 2!) |
countof("ababa", "ab", "normal") |
2 |
countof("ababa", "aba") |
2 |
countof("ababa", "aba", "regex") |
1 |
countof("abcabc", "a.c", "regex") |
2 |