Strings1
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This document discusses strings in C++. It explains that a string is a class that can be thought of as a new type of variable to store text. Strings store characters in an array and functions like length() can return the size. Strings can be concatenated using + or assigned using =. The getline() function reads a whole line of input including whitespace. Dot functions operate on specific string objects.
![Strings
The internal construction of a string (or
cstring) is really an array of characters.
The first character of string s is s[0].
string s = “Hello”;
cout<<s[4]; //prints the letter o
To find the length of a string s we can use
the functions .length() or .size()
int x = s.length(); gives x the value of the
size of the string s (in this case, 5).](https://image.slidesharecdn.com/strings1-140424104553-phpapp01/85/Strings1-3-320.jpg)
Strings1
- 1. CS111 Lab Strings Instructor: Michael Gordon
- 2. The String class A class can be thought of as new type of variable that you can create. C++ is also called “C with classes” We’ve used one kind of class already: the string class, which is not in C. string and its functions are built into C++. C had C-strings, which can be found in the cstring library.
- 3. Strings The internal construction of a string (or cstring) is really an array of characters. The first character of string s is s[0]. string s = “Hello”; cout<<s[4]; //prints the letter o To find the length of a string s we can use the functions .length() or .size() int x = s.length(); gives x the value of the size of the string s (in this case, 5).
- 4. Strings To “concatenate” two strings s1 and s2: string s3 = s1 + s2; string s1 = “race”; string s2 = “car”; string s3 = s1 + s2; cout<<s3; //prints racecar
- 5. String examples string first, last, name; cout<<"Enter your first name:"; cin>>first; cout<<"Enter your last name:"; cin>>last; cout<<"Hi, "+first+" "+last; //concatenation
- 6. getline() cin reads the typed string only until the first whitespace. If you want the whole string including those whitespaces, you can use: getline(cin, stringname); cout<<“Enter your name:”; getline(cin, fullname); Use fullname instead of first and last.
- 7. “dot” functions With strings we start dealing with a new kind of function call. These functions operate on a specific “object” (an instance of a class). We write the object name (e.g. the variable name of the string) followed by period and the function call (no space before or after the period).
- 8. More functions s1.find(string s2) – returns the index of the beginning of s2 in s1. s1 = “hello”; s1.find(“lo”) – returns 3 s1.insert(int i, string s2) – inserts s2 into s1 at index I s1.at(int i) – returns the character at index i in string s1