lect8_2

# lect8_2 - Arrays and Pointers 1 Arrays and Pointers In this...

This preview shows pages 1–3. Sign up to view the full content.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: Arrays and Pointers 1 Arrays and Pointers In this part we investigate the relationship between pointers and arrays. Using const in pointer declarations Consider the following declaration. int a = 10; // int variable a is modifiable const int b = 20; // int variable b is not modifiable Variable a can be modified by a statement, such as a = 25; . The value of b cannot be modified any where in the program, since b is declared as a const variable. Note that any const variable has to be initialized at the time of its declaration. For example, look at the following code segment. int a; a = 10; // this is OK const int b; // illegal - will not compile b = 20; // will not compile Since b is a const , we must initialize b with a value during its declaration. Placing const in a pointer declaration In a pointer declaration, const can be used in two different places, with two different meanings. Consider the following code segment. int a = 10, b = 20; const int *pc; // const placed at the beginning pc = &amp;a; int *const cp = &amp;b; //const placed before pointer name Arrays and Pointers 2 The two integer variables and the pointers pointing to them is depicted below. It helps to read the pointer declarations backwards. The declaration const int *pc; tells the compiler that pc is a pointer to an interger constant . Here the const qualifier is for the target variable, but not for the pointer. What does this mean? When the pointer pc is pointing to a target variable, such as a , we cannot modify the target variable using pc . That is, a statement such as *pc = 44; // this will not compile will not compile, because *pc , the target variable, behaves like a const (unmodifiable) variable. Note that the following statement compiles because a is not a const variable....
View Full Document

## lect8_2 - Arrays and Pointers 1 Arrays and Pointers In this...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online