![ARRAY
C++ Arrays
Arrays are used to store multiple values in a single variable,
instead of declaring separate variables for each value.
To declare an array, define the variable type, specify the
name of the array followed by square brackets and
specify the number of elements it should store:
Example:- string cars[4];](https://image.slidesharecdn.com/chapter5-240528034243-d6bc0adf/85/CHAPTER-5-oop-chapter-5-programming-sem2-2-320.jpg)
![ We have now declared a variable that holds an array of four strings. To insert values to it, we can use an
array literal - place the values in a comma-separated list, inside curly braces:
Example:- string cars[4] = {"Volvo", "BMW", "Ford", "Mazda"};
To create an array of three integers, you could write:
Example:- int myNum[3] = {10, 20, 30};
Access the Elements of an Array
You access an array element by referring to the index number inside square brackets [].
This statement accesses the value of the first element in cars:
Example:- string cars[4] = {"Volvo", "BMW", "Ford", "Mazda"};
cout << cars[0];
// Outputs Volvo
Change an Array Element
To change the value of a specific element, refer to the index number:
Example :- cars[0] = "Opel";
Example :- string cars[4] = {"Volvo", "BMW", "Ford", "Mazda"};
cars[0] = "Opel";
cout << cars[0];
// Now outputs Opel instead of Volvo](https://image.slidesharecdn.com/chapter5-240528034243-d6bc0adf/85/CHAPTER-5-oop-chapter-5-programming-sem2-3-320.jpg)
![C++ Arrays and Loops
Loop Through an Array
You can loop through the array elements with the for loop.
The following example outputs all elements in the cars array:
Example:- string cars[5] =
{"Volvo", "BMW", "Ford", "Mazda", "Tesla"};
for (int i = 0; i < 5; i++) {
cout << cars[i] << "n";
}](https://image.slidesharecdn.com/chapter5-240528034243-d6bc0adf/85/CHAPTER-5-oop-chapter-5-programming-sem2-4-320.jpg)
![The foreach Loop
There is also a "for-each loop" (introduced in C++ version 11 (2011),
which is used exclusively to loop through elements in an array:
Syntax :- for (type variableName : arrayName) {
// code block to be executed
}
The following example outputs all elements in an array, using a "for-
each loop":
Example : - int myNumbers[5] = {10, 20, 30, 40, 50};
for (int i : myNumbers) {
cout << i << "n";
}](https://image.slidesharecdn.com/chapter5-240528034243-d6bc0adf/85/CHAPTER-5-oop-chapter-5-programming-sem2-5-320.jpg)
![Get the Size of an Array
To get the size of an array, you can use the sizeof() operator:
Example :- int myNumbers[5] = {10, 20, 30, 40, 50};
cout << sizeof(myNumbers);
output:- 20
Why did the result show 20 instead of 5, when the array contains 5 elements?
It is because the sizeof() operator returns the size of a type in bytes. You
learned from the Data Types chapter that an int type is usually 4 bytes, so from
the example above, 4 x 5 (4 bytes x 5 elements) = 20 bytes.
To find out how many elements an array has, you have to divide the size of
the array by the size of the data type it contains:
Example:- int myNumbers[5] = {10, 20, 30, 40, 50};
int getArrayLength = sizeof(myNumbers) / sizeof(int);
cout << getArrayLength;
output:- 5](https://image.slidesharecdn.com/chapter5-240528034243-d6bc0adf/85/CHAPTER-5-oop-chapter-5-programming-sem2-6-320.jpg)
CHAPTER 5 oop chapter 5 programming sem2
- 1. BY THEISA
- 2. ARRAY C++ Arrays Arrays are used to store multiple values in a single variable, instead of declaring separate variables for each value. To declare an array, define the variable type, specify the name of the array followed by square brackets and specify the number of elements it should store: Example:- string cars[4];
- 3. We have now declared a variable that holds an array of four strings. To insert values to it, we can use an array literal - place the values in a comma-separated list, inside curly braces: Example:- string cars[4] = {"Volvo", "BMW", "Ford", "Mazda"}; To create an array of three integers, you could write: Example:- int myNum[3] = {10, 20, 30}; Access the Elements of an Array You access an array element by referring to the index number inside square brackets []. This statement accesses the value of the first element in cars: Example:- string cars[4] = {"Volvo", "BMW", "Ford", "Mazda"}; cout << cars[0]; // Outputs Volvo Change an Array Element To change the value of a specific element, refer to the index number: Example :- cars[0] = "Opel"; Example :- string cars[4] = {"Volvo", "BMW", "Ford", "Mazda"}; cars[0] = "Opel"; cout << cars[0]; // Now outputs Opel instead of Volvo
- 4. C++ Arrays and Loops Loop Through an Array You can loop through the array elements with the for loop. The following example outputs all elements in the cars array: Example:- string cars[5] = {"Volvo", "BMW", "Ford", "Mazda", "Tesla"}; for (int i = 0; i < 5; i++) { cout << cars[i] << "n"; }
- 5. The foreach Loop There is also a "for-each loop" (introduced in C++ version 11 (2011), which is used exclusively to loop through elements in an array: Syntax :- for (type variableName : arrayName) { // code block to be executed } The following example outputs all elements in an array, using a "for- each loop": Example : - int myNumbers[5] = {10, 20, 30, 40, 50}; for (int i : myNumbers) { cout << i << "n"; }
- 6. Get the Size of an Array To get the size of an array, you can use the sizeof() operator: Example :- int myNumbers[5] = {10, 20, 30, 40, 50}; cout << sizeof(myNumbers); output:- 20 Why did the result show 20 instead of 5, when the array contains 5 elements? It is because the sizeof() operator returns the size of a type in bytes. You learned from the Data Types chapter that an int type is usually 4 bytes, so from the example above, 4 x 5 (4 bytes x 5 elements) = 20 bytes. To find out how many elements an array has, you have to divide the size of the array by the size of the data type it contains: Example:- int myNumbers[5] = {10, 20, 30, 40, 50}; int getArrayLength = sizeof(myNumbers) / sizeof(int); cout << getArrayLength; output:- 5