Editing C syntax (section)

===Pointers===
In declarations the asterisk modifier ({{code|*}}) specifies a pointer type. For example, where the specifier {{code|int}} would refer to the integer type, the specifier {{code|int*}} refers to the type "pointer to integer". Pointer values associate two pieces of information: a memory address and a data type. The following line of code declares a pointer-to-integer variable called ''ptr'':

<syntaxhighlight lang=C>int *ptr;</syntaxhighlight>

====Referencing====
When a non-static pointer is declared, it has an unspecified value associated with it. The address associated with such a pointer must be changed by assignment prior to using it. In the following example, ''ptr'' is set so that it points to the data associated with the variable ''a'':

<syntaxhighlight lang=C>
int a = 0;
int *ptr = &a;
</syntaxhighlight>

In order to accomplish this, the "address-of" operator (unary {{code|&}}) is used. It produces the memory location of the data object that follows.

====Dereferencing====
The pointed-to data can be accessed through a pointer value. In the following example, the integer variable ''b'' is set to the value of integer variable ''a'', which is 10:

<syntaxhighlight lang=C>
int a=10;
int *p;
p = &a;
int b = *p;
</syntaxhighlight>

In order to accomplish that task, the unary [[dereference operator]], denoted by an asterisk (*), is used. It returns the data to which its operand—which must be of pointer type—points. Thus, the expression *''p'' denotes the same value as ''a''. Dereferencing a [[null pointer]] is illegal.