Strings vs CStrings

Question 1

String Constructors

default (1) string();

copy (2) string (const string& str);

substring (3) string (const string& str, size_t pos, size_t len = npos);

from c-string (4) string (const char* s);

from buffer (5) string (const char* s, size_t n);

fill (6) string (size_t n, char c);

range (7) template string (InputIterator first, InputIterator last);

initializer list (8) string (initializer_list il);

move (9) string (string&& str) noexcept;

Answer 1

Question 2

Function of:

1. stof
2. stold
3. stoi
4. strtof

Answer 2

1. Convert string to float
2. String to long double
3. string to int
4. ?

Question 3

include-ing the two

Answer 3

C-strings (#include <cstring>)</cstring>

C++ strings (#include <string> )</string>

Question 4

1. Declaring a C-string variable
2. Declaring a C++ string object

Answer 4

1. char str[10];
2. string str;

Question 5

Initializing a C-string variable

Answer 5

char str1[11] = “Call home!”;

char str2[] = “Send money!”;

char str3[] = {‘O’, ‘K’, ‘\0’};

Last line above has same effect as:

char str3[] = “OK”;

Question 6

Initializing a C++ string object

Answer 6

string str1(“Call home!”);

string str2 = “Send money!”;

string str3(“OK”);

Question 7

Assigning to a C-string variable

Answer 7

Can’t do it, i.e., can’t do this:

char str[10];

str = “Hello!”;

Question 8

Assigning to a C++ string object

Answer 8

string str;

str = “Hello”;

str = otherString;

Question 9

Concatenating two C-strings

Answer 9

strcat(str1, str2);

strcpy(str, strcat(str1, str2));

Question 10

Concatenating two C++ string objects

Answer 10

str1 += str2;

str = str1 + str2;

Question 11

Copying a C-string variable

Answer 11

char str[20];

strcpy(str, “Hello!”);

strcpy(str, otherString);

Question 12

Copying a C++ string object

Answer 12

string str;

str = “Hello”;

str = otherString;

Question 14

Accessing a single character (cstring)

Answer 14

str[index]

Question 15

Accessing a single character(Strinng Obj)

Answer 15

str[index]

str.at(index)

str(index, count)

]

Question 16

Comparing two C-strings vs Comparing two C++ string objects

Answer 16

Question 17

Finding the length of a C-string

Answer 17

strlen(str)

Question 18

Finding the length of a C++ string object

Answer 18

str.length()

Question 19

In what follows, keep in mind that cin ignores white space when reading a string, while cin.get(), cin.getline() and getline() do not. Remember too that cin.getline() andgetline() consume the delimiter while cin.get() does not. Finally, cin can be replaced with any open input stream, since file input with inFile, say, behaves in a manner completely analogous to the corresponding behavior of cin. Analogously, in the output examples given immediately above, cout could be replaced with any text output stream variable, say outFile. In all cases, numCh is the maximum number of characters that will be read.

Answer 19