PHP considers null is equal to zero.
IS NULL considered 0?
and zero is an integer constant. So basically NULL is in pointer terms. In SQL databases this difference is very important. NULL in SQL basically means that the value is ‘undefined’ whereas is a defined value.
What is null in PHP?
NULL ¶ The special null value represents a variable with no value. null is the only possible value of type null. A variable is considered to be null if: … it has not been set to any value yet.
IS NULL empty in PHP?
empty() This function checks whether a variable evaluates to what PHP sees as a “falsy”(a.k.a empty) value. This being said, a variable is empty if it’s undefined, null, false, 0 or an empty string.
IS null or 0 SQL?
In SQL Server, NULL value indicates an unavailable or unassigned value. The value NULL does not equal zero (0), nor does it equal a space (‘ ‘). Because the NULL value cannot be equal or unequal to any value, you cannot perform any comparison on this value by using operators such as ‘=’ or ‘<>’.
What does != 0 mean in C?
It is the ascii value of null. It is use to identify whether there is null present in the string or not while performing string oeration. For example: for(i=0;string[i] != ‘