instr ( haystack_string_expression , needle_string_expression )
instr ( haystack_string_expression , needle_string_expression , start_expression )
instr ( haystack_string_expression , needle_string_expression , start_expression , boolean_expression)

returns integer_expression

Check to see if the string needle_string_expression is contained in the string haystack_string_expression. If it is, then this function will return the index of starting character of the first place where needle_string_expression occurs. Otherwise, this function will return 0.

You may optionally specify a starting location for the search to begin start_expression. If the start is 1 or greater the search will begin from the specified character from the start. If the start is < 0 then the search will begin from the nth character from the end. The search will ALWAYS look forward.

An optional boolean_expression may be used to specify that the search will treat upper and lower case letters the same.

String indices begin at 1.

print instr("Hello", "lo")
print instr("101,222,333",",",5)

will display

4
8