Array-specialization of startsWith with default predicate.
const x = "beta version"; assert(x.startsWith("beta")); assert(x.startsWith('b')); assert(!x.startsWith("_")); assert(!"".startsWith("_")); assert(!"".startsWith('_'));
https://d.godbolt.org/z/ejEmrK
See Implementation
Array-specialization of startsWith with default predicate.