How to test a object name is an executable ?

[Budi]

How  do we test an object name / string is an executable, as tried it
won't work:

$ [[ -x cp ]] &&echo YES
$
$ [[ -x ls ]] &&echo YES



also tried it hard won't be correct way:

$ >/dev/null type ls && echo YES
YES

$ >/dev/null type -fat && echo YES
YES
This the very falling failure thanks for help before