Is 0123456789012345 numeric?
bool(true)
int(1)
Is ABCDEFGHIJK numeric?
bool(false)
int(0)
Is 01234567 numeric?
bool(true)
int(1)
Is ABC numeric?
bool(false)
int(0)
Is 1ABC numeric?
bool(false)
int(0)
--
Is ABCDEFGHIJKL numeric?
bool(false)
int(0)
Is 012345 numeric?
bool(true)
int(0)
Is AB numeric?
bool(false)
int(0)
Is 01234567890123456 numeric?
bool(true)
int(1)
Output for 8.3.5
Warning: PHP Startup: Unable to load dynamic library 'sodium.so' (tried: /usr/lib/php/8.3.5/modules/sodium.so (libsodium.so.23: cannot open shared object file: No such file or directory), /usr/lib/php/8.3.5/modules/sodium.so.so (/usr/lib/php/8.3.5/modules/sodium.so.so: cannot open shared object file: No such file or directory)) in Unknown on line 0
Is 0123456789012345 numeric?
bool(true)
int(1)
Is ABCDEFGHIJK numeric?
bool(false)
int(0)
Is 01234567 numeric?
bool(true)
int(1)
Is ABC numeric?
bool(false)
int(0)
Is 1ABC numeric?
bool(false)
int(0)
--
Is ABCDEFGHIJKL numeric?
bool(false)
int(0)
Is 012345 numeric?
bool(true)
int(0)
Is AB numeric?
bool(false)
int(0)
Is 01234567890123456 numeric?
bool(true)
int(1)