Check a large number is divisible by 16 or not | Function to find that number divisible by 16 or not ; Empty string ; If there is double digit ; If there is triple digit ; If number formed by last four digits is divisible by 16. ; Driver code
< ? php function check ( $ str ) { $ n = strlen ( $ str ) ; if ( $ n == 0 && $ n == 1 ) return false ; if ( $ n == 2 ) return ( ( ( $ str [ $ n - 2 ] - '0' ) * 10 + ( $ str [ $ n - 1 ] - '0' ) ) % 16 == 0 ) ; if ( $ n == 3 ) return ( ( ( $ str [ $ n - 3 ] - '0' ) * 100 + ( $ str [ $ n - 2 ] - '0' ) * 10 + ( $ str [ $ n - 1 ] - '0' ) ) % 16 == 0 ) ; $ last = $ str [ $ n - 1 ] - '0' ; $ second_last = $ str [ $ n - 2 ] - '0' ; $ third_last = $ str [ $ n - 3 ] - '0' ; $ fourth_last = $ str [ $ n - 4 ] - '0' ; return ( ( $ fourth_last * 1000 + $ third_last * 100 + $ second_last * 10 + $ last ) % 16 == 0 ) ; } $ str = "769528" ; $ x = check ( $ str ) ? " Yes " : " No ▁ " ; echo ( $ x ) ; ? >