![Arrays
Array
A collection of same datatype data, having a common name, a
unique index and are store in consecutive memory locations
To refer to an element
Specify array name and position number (index)
Format: arrayname[ position number ]
First element at position 0
N-element array c
c[ 0 ], c[ 1 ] … c[ n - 1 ]
Nth element as position N-1](https://image.slidesharecdn.com/lecture2-230405132210-10aa082a/85/Lecture-2-8-Arrays-pdf-2-320.jpg)
![Arrays
Array elements are treated like other variables
Assignment, printing for an integer array c
c[ 0 ] = 3;
cout << c[ 0 ];
Can perform operations inside subscript
c[ 5 – 2 ] same as c[3]](https://image.slidesharecdn.com/lecture2-230405132210-10aa082a/85/Lecture-2-8-Arrays-pdf-3-320.jpg)
![Declaring Arrays
When declaring arrays, specify
Name
Type of array
Any data type
Number of elements
type arrayName[ arraySize ];
Declaring multiple arrays of same type
Use comma separated list, like regular variables
int c[ 10 ]; // array of 10 integers
float d[ 3284 ]; // array of 3284 floats
int b[ 100 ], x[ 27 ];](https://image.slidesharecdn.com/lecture2-230405132210-10aa082a/85/Lecture-2-8-Arrays-pdf-4-320.jpg)
![Initializing arrays
For loop
Set each element
Initializer list
Specify each element when array declared
If not enough initializers, rightmost elements 0
If too many syntax error
To set every element to same value
If array size omitted, initializers determine size
5 initializers, therefore 5 element array
int n[ 5 ] = { 1, 2, 3, 4, 5 };
int n[ 5 ] = { 0 };
int n[] = { 1, 2, 3, 4, 5 };](https://image.slidesharecdn.com/lecture2-230405132210-10aa082a/85/Lecture-2-8-Arrays-pdf-5-320.jpg)
![Passing Arrays to Functions
Specify name without brackets
To pass array myArray to myFunction
Array size usually passed, but not required
Useful to iterate over all elements
Arrays passed-by-reference
Functions can modify original array data
Value of name of array is address of first element
Function knows where the array is stored
Can change original memory locations
Individual array elements passed-by-value
Like regular variables
int myArray[ 24 ];
myFunction( myArray, 24 );
square( myArray[3] );](https://image.slidesharecdn.com/lecture2-230405132210-10aa082a/85/Lecture-2-8-Arrays-pdf-6-320.jpg)
![Passing Arrays to Functions
Functions taking arrays
Function prototype
Names optional in prototype
Both take an integer array and a single integer
No need for array size between brackets
Ignored by compiler
If declare array parameter as const
Cannot be modified (compiler error)
void modifyArray( int b[], int arraySize );
void modifyArray( int [], int );
void doNotModify( const int [] );](https://image.slidesharecdn.com/lecture2-230405132210-10aa082a/85/Lecture-2-8-Arrays-pdf-7-320.jpg)
Lecture 2.8 Arrays.pdf
- 1. ARRAYS Lecture 2.8 Prepared by: Mian Saeed Akbar
- 2. Arrays Array A collection of same datatype data, having a common name, a unique index and are store in consecutive memory locations To refer to an element Specify array name and position number (index) Format: arrayname[ position number ] First element at position 0 N-element array c c[ 0 ], c[ 1 ] … c[ n - 1 ] Nth element as position N-1
- 3. Arrays Array elements are treated like other variables Assignment, printing for an integer array c c[ 0 ] = 3; cout << c[ 0 ]; Can perform operations inside subscript c[ 5 – 2 ] same as c[3]
- 4. Declaring Arrays When declaring arrays, specify Name Type of array Any data type Number of elements type arrayName[ arraySize ]; Declaring multiple arrays of same type Use comma separated list, like regular variables int c[ 10 ]; // array of 10 integers float d[ 3284 ]; // array of 3284 floats int b[ 100 ], x[ 27 ];
- 5. Initializing arrays For loop Set each element Initializer list Specify each element when array declared If not enough initializers, rightmost elements 0 If too many syntax error To set every element to same value If array size omitted, initializers determine size 5 initializers, therefore 5 element array int n[ 5 ] = { 1, 2, 3, 4, 5 }; int n[ 5 ] = { 0 }; int n[] = { 1, 2, 3, 4, 5 };
- 6. Passing Arrays to Functions Specify name without brackets To pass array myArray to myFunction Array size usually passed, but not required Useful to iterate over all elements Arrays passed-by-reference Functions can modify original array data Value of name of array is address of first element Function knows where the array is stored Can change original memory locations Individual array elements passed-by-value Like regular variables int myArray[ 24 ]; myFunction( myArray, 24 ); square( myArray[3] );
- 7. Passing Arrays to Functions Functions taking arrays Function prototype Names optional in prototype Both take an integer array and a single integer No need for array size between brackets Ignored by compiler If declare array parameter as const Cannot be modified (compiler error) void modifyArray( int b[], int arraySize ); void modifyArray( int [], int ); void doNotModify( const int [] );
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