This section on online C++ quiz on “String Class”. One shall practice these online quizzes to improve their C++ programming skills needed for various interviews (campus interviews, walk-in interviews, company interviews), placements, entrance exams and other competitive exams. These questions can be attempted by anyone focusing on learning C++ programming language. They can be a beginner, fresher, engineering graduate or an experienced IT professional. Our C++ quiz comes with the detailed explanation of the answers which helps in better understanding of C++ concepts.
Here is a listing of online C++ quiz on “String Class” along with answers, explanations and/or solutions:
1. How many types of representation are in the string?
a) 1
b) 2
c) 3
d) 4
Answer: b
Clarification: C++ provides the following two types of string representations. They are C-style character string and string class type with Standard C++.
2. What is the header file for the string class?
a) #include
b) #include
c) #include
d) #include
Answer: c
Clarification: #include is the header file for the string class.
3. Which is used to return the number of characters in the string?
a) length
b) size
c) both size & length
d) name
Answer: c
Clarification: Both will return the number of characters that conform to the string’s content.
4. What will be the output of the following C++ code?
-
#include
-
#include
-
using namespace std;
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int main ()
-
{
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char str1[10] = "Hello";
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char str2[10] = "World";
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char str3[10];
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int len ;
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strcpy( str3, str1);
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strcat( str1, str2);
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len = strlen(str1);
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cout << len << endl;
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return 0;
-
}
a) 5
b) 55
c) 11
d) 10
Answer: d
Clarification: In the program, We are concatenating the str1 and str2 and printing
it’s total length. So the length is 10.
Output:
$ g++ stri.cpp
$ a.out
10
5. What will be the output of the following C++ code?
-
#include
-
#include
-
using namespace std;
-
int main ()
-
{
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string str ("microsoft");
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string::reverse_iterator r;
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for (r = str.rbegin() ; r < str.rend(); r++ )
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cout << *r;
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return 0;
-
}
a) microsoft
b) micro
c) tfosorcim
d) tfos
Answer: c
Clarification: ‘rbegin’ is used to reverse the given the string.
Output:
$ g++ stri1.cpp
$ a.out
tfosorcim
6. What will be the output of the following C++ code?
-
#include
-
#include
-
using namespace std;
-
int main ()
-
{
-
string str ("nobody does like this");
-
string key ("nobody");
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size_t f;
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f = str.rfind(key);
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if (f != string::npos)
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str.replace (f, key.length(), "everybody");
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cout << str << endl;
-
return 0;
-
}
a) nobody does like this
b) nobody
c) everybody
d) everybody does like this
Answer: d
Clarification: rfind is used to find the characters in the string and replace is used to replace with certain characters.
Output:
$ g++ stri2.cpp
$ a.out
everybody does like this
7. What will be the output of the following C++ code?
-
#include
-
#include
-
using namespace std;
-
int main ()
-
{
-
string str ("steve jobs is legend");
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string::iterator it;
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str.erase (str.begin()+ 5, str.end()-7);
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cout << str << endl;
-
return 0;
-
}
a) jobs is
b) steve legend
c) steve
d) steve jobs is
Answer: b
Clarification: In this program, We are leaving the first 5 characters and last 7 characters and we are erasing the remaining the characters.
Output:
$ g++ stri3.cpp
$ a.out
steve legend
8. What will be the output of the following C++ code?
-
#include
-
#include
-
using namespace std;
-
int main ()
-
{
-
string str ("Microsoft");
-
for (size_t i = 0; i < str.length();)
-
{
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cout << str.at(i-1);
-
}
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return 0;
-
}
a) M
b) Microsoft
c) Micro
d) runtime error
Answer: d
Clarification: This program will terminate because the cout element is out of range.
9. What will be the output of the following C++ code?
-
#include
-
#include
-
using namespace std;
-
int main ()
-
{
-
string str ("Ubuntu");
-
cout << str.capacity();
-
cout << str.max_size();
-
return 0;
-
}
a) 61073741820
b) 51073741820
c) 6 and max size depends on compiler
d)
15
9223372036854775807
View Answer
Answer: d
Clarification: str.capacity() returns the size of the storage space currently allocated for the string, expressed in terms of bytes and capacity of the string may be equal or greater. The max_size() returns the max size of the string.
Output:
$ g++ stri5.cpp
$ a.out
15
9223372036854775807
10. Which method do we use to append more than one character at a time?
a) append
b) operator+=
c) data
d) both append & operator+=
Answer: d
Clarification: C++ allows to append more characters to string using both inbuilt append() function and using operator overloaded += operator.
