1. Strings Skill Area 313 Part C
Materials Prepared by Dhimas Ruswanto, BMm

2. Lecture Overview
Char
Strings

3. Char
A sequence of characters is often referred to as a character “string”.
A string is stored in an array of type char ending with the null character “\0”.

4. Char
A string containing a single character takes up 2 bytes of storage.

5. Char

6. Char
A string constant is a sequence of characters enclosed in double quotes.
E.g.
char s1[2]=“a”; //takes 2 bytes of storage
On the other hand, the character, in single quotes:
char s2=‘a’; //takes only a byte of storage

7. Char

8. Char
char message1[12] = “Hello world”; cout << message1 << endl; char message2[12]; cin >> message2; //type “Hello” as input

9. getline
The function getline can be used to read an entire line of input into a string variable.
The getline function has three parameters:
The first specifies the area into which the string is to be read.
The second specifies the maximum number of characters, including the string delimiter.
The third specifies an optional terminating character. If not included, getline stops at “\n”.

10. getline
char A_string[80]; //80 is the size of A_string cout << “Enter some words in a string: \n”; cin.getline (A_string, 80); cout << A_string << “\nEnd of Output\n”; Output: Enter some words in a string: This is a test. End of Output

11. getline char lastName[30], firstName[30];
cout << “Enter a name <last,first>: \n”;
cin.getline (lastName, sizeof(lastName));
cin.getline (firstName, sizeof(firstName));
cout << “Here is the name you typed: \n\t|”
<< firstName << “ ” <<lastName << “|\n”;
Output:
Enter a name <last, first>:
Chan Anson
Here is the name you typed:
|Anson Chan|

12. Strings #include <string> //string header file
string mystr; //declare string
getline (cin, mystr); //getline for string

13. Example (Strings)
#include <iostream> #include <string> using namespace std; int main () { string mystr; cout << "What's your name? "; getline (cin, mystr); cout << "Hello " << mystr << ".\n"; cout << "What is your favorite team? "; cout << "I like " << mystr << " too!\n"; return 0; }

14. stringstream
The standard header file <sstream> defines a class called stringstream that allows a string-based object to be treated as a stream. This way we can perform extraction or insertion operations from/to strings, which is especially useful to convert strings to numerical values and vice versa.
For example, if we want to extract an integer from a string we can write:
string mystr ("1204");
int myint;
stringstream(mystr) >> myint;

15. Example (stringstream)
#include <iostream> #include <string> #include <sstream> using namespace std; int main () { string mystr; float price=0; int quantity=0; cout << "Enter price: "; getline (cin,mystr); stringstream(mystr) >> price; cout << "Enter quantity: "; stringstream(mystr) >> quantity; cout << "Total price: " << price*quantity <<endl; return 0; }

16. strcpy char name1[16], name2 [16];
strcpy(name2, name1) //copies string name2 into string name1
Name1[16]=“Chan Tai Man”
Name2[16]=“ ”
strcpy(name2, name1);

17. Examples
Exchange the value of 2 numbers; int a,b,temp; cout<< “Enter a: ”; cin >> a; cout << “Enter b: “; cin >> b; temp=a; a=b; b=temp; cout << a <<endl; cout << b << endl;

18. --- continue to next slide ---