Language reference
InStr (find substring position)
Syntax
InStr(<string>, <find>)
InStr(<start>, <string>, <find>)
π InStr(email, "@") → at_pos (Users)Description
InStr finds where one string appears inside another and returns its position (counting from 1), or 0 if it is not found. Use it to locate a delimiter — the @ in an email, a separator in a code — often as the input to Mid/Left/Right.
Technical Description
InStr(s, find) → NUMBER returns the 1-based index of the first occurrence of find in s, or 0 if absent. The three-argument form InStr(start, s, find) begins searching at the 1-based start position. NULL arguments return NULL. PURE, DETERMINISTIC.
Examples
Position of the @ in an email:
π InStr(email, "@") → at_pos (Users)PROJECT InStr(email, "@") -> at_pos (Users)Split a "name:value" pair — get the name before the colon:
π Left(pair, InStr(pair, ":") - 1) → name (Pairs)PROJECT Left(pair, InStr(pair, ":") - 1) -> name (Pairs)Find a later occurrence (search from position 5):
π InStr(5, path, "/") → next_slash (Paths)PROJECT InStr(5, path, "/") -> next_slash (Paths)Limitations
Returns 0 (not NULL) when the substring is absent — guard for 0 before using it as an index. STRING arguments; a NULL argument returns NULL.
Alternatives
IsNumeric / pattern checks for validation; Replace to substitute rather than locate.