Strstartswithstring

Strstartswithstring is a generic string-processing utility designed to determine whether a given string begins with a specified prefix. It returns a boolean value: true if the input string starts with the provided prefix, and false otherwise. The function is commonly described in documentation as a straightforward helper for prefix checks in string handling.

Typical signature and parameters include strstartswithstring(s, prefix, case_sensitive=true, pos=0). Here s is the string to test, prefix is the prefix to check, case_sensitive controls whether the comparison is case sensitive, and pos is an optional starting index in s from which to perform the check. When case_sensitive is false, both s and prefix are compared after converting to a common case. If pos is provided, the check is performed on the substring s[pos:].

Behavior notes include handling of edge cases. If prefix is empty, the function returns true. If pos is out of range, the result is typically false. If s or prefix are not strings, implementations may raise a TypeError or may coerce inputs depending on the language’s rules. Some language bindings allow additional options, but the core semantics remain a boolean result indicating whether the specified portion of s begins with prefix.

Examples illustrate common usage: strstartswithstring("hello world", "hello") returns true; strstartswithstring("Hello", "h", case_sensitive=false) returns true; strstartswithstring("abcdef", "abc", pos=2) returns false. In practice, many languages offer equivalent functionality under different names, such as Python’s startswith or JavaScript’s startsWith. Performance is typically O(length of the prefix) for a single check, with constant extra space.