C# Programming Questions and Answers

1

Which of the following string() method are used to compare two strings with each other?

a

CopyTo()

b

Copy()

c

Compare()

d

CompareTo()

correct answer b

Creates a new string by copying one string to another.

2

Which of the following statement is correct about a string in C#.NET?

a

The System.Array class is used to represent a string

b

A string has a zero-based index

c

A number cannot be represented in the form of a string

d

A string is mutable because it can be modified once it has been created

correct answer b

Answer: Option (B)

3

Choose Output for the following set of code :

staticvoid Main(string[] args)

{

string s1 ="Hello"+" I "+"Love"+" ComputerScience ";

Console.WriteLine(s1);

Console.ReadLine();

}

a

HelloILoveComputerScience

b

Hello I Love ComputerScience

c

Compile time error

d

Hello

correct answer b

Here ‘+’ defined operator works as concatenation for strings.
Output : Hello I Love ComputerScience.

4

Which of the following statements are correct?

a

String is value type

b

String literals can contain any character literal including escape sequences

c

The equality operators are defined to compare values of string objects as well as references

d

All of the mentioned

correct answer b

Answer: Option (B)

5

Which of these operators can be used to concatenate two or more String objects?

a

+

b

+=

c

&

d

||

correct answer a

string s1 = “Hello”+ ” I ” + “Love” + ” ComputerScience “;
Console.WriteLine(s1);
Hello I Love ComputerScience.

6

The Method use to remove white space from string?

a

Split()

b

Substring()

c

Trim()

d

TrimStart()

correct answer c

Perfectly removes a whitespace from string whereas TrimStart() removes a string of characters from the end of the string.

7

What is output for the following set of code:

staticvoid Main(string[] args)

{

string s1 =" Cshr ";

string s2 = s1.Insert(3 , " a ");

string s3 = s2.Insert(5 , " p ");

for(int i =0;i < s3.Length; i++)

Console.WriteLine(s3[i]);

Console.ReadLine();

}

a

Cshar

b

CsharP

c

Csharp

d

Cshrap

correct answer c

Insertion of character ‘a’ at postion ‘3’ using insert() which returns a new string with a substring inserted at a specified location.
Output: Csharp

8

What is output for the following set of code?

staticvoid Main(string[] args)

{

string s1 ="Hello";

string s2 ="hello";

if(s1 == s2)

Console.WriteLine("Equal");

else

Console.WriteLine("Unequal");

if(s1.Equals(s2))

Console.WriteLine("Equal");

else

Console.WriteLine("Unequal");

Console.ReadLine();

}

a

Equal
Unequal

b

Unequal
Equal

c

Equal
Equal

d

Unequal
Unequal

correct answer d

In first comparison it is being checked either two strings are equal or not but in second comparison it is checked whether two references are equal or not.
Output: Unequal
Unequal

9

Correct way to find if contents of two strings are equal ?

a

if (s1 = s2)

b

if (s1 == s2)

c

if (strcmp (s1 ,s2))

d

if ( s1 is s2)

correct answer b,c

“==” operator used to compare length of two strings and strcmp() is the inbuilt method derived from string class.