Strings

Strings (std::string) in C++ are objects, sparing us from details like null terminators. #include <string> to use.

Strings can be arbitrarily long. The C++ library handles the memory (allocating and adjusting, freeing when string goes out of scope)

Initializing

string s1 = "world";
string s2("hello");
string s3(3,'a'); // s3 is "aaa"
string s4; // empty string ""
string s5(s2); // copies s2 into s5

s1 is initialized in two steps. s2 is called with constructors.

Uses

s = "wow"	// assign literal to string
cin >> s	// put one whitespace-deliminted input word in s
cout << s	// write s to standard out
getline(cin,s)	//read to end of line from stdin, store in s
s1 = s2		//copy contents of s2 into s1
s1 + s2		// return new string: s1 concatenated with s2
s1 += s2	// same as s1.append(s2)
== != <> <= >=	// relational operators; alphabetical order

s.capacity() returns the bytes of memory allocated s.substr(offset, howmany) gives substring of s s.c_str() returns C-style const char * version s[5] accesses the 6th character in string s.at(5) does the same, additionally doing a "bounds check." This is preferred over s[5].

Commonly used member functions: s.length() returns the length of the string (as a long unsigned value) empty returns false when there is at least 1 character append like += push_back like append for a single character clear set to empty string insert insert one string in middle of another erase removes stretch of characters from string replace replace a substring with a given string