php - Find the highest set bit -

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i have 5 different values saved bits 10010. value int database (cannot change that) 24 means 11000 know can biggest bit here using

if ((decbin($d) & 16) == 16)

but if first 0 have check next bit, , if 0 have ...

so after have block of ifs , if there more bits block bigger. there simple way "id" (or value, not matter) of highest bit 1?

yes. compute base 2 logarithm of number , floor it:

$highbit = floor(log($d, 2));

if $highbit, instance, 5, means 5th bit highest bit set 1.


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