Integ Programming

Question 1

is a set of fixed number of values called elements that can be accessed using integer index

Answer 1

array

Question 2

on an array are
of the same data type

Answer 2

Elements

Question 3

is used to store multiple values of the same data type at a time
without declaring a different variable name for each value. Array elements can be of any data type

Answer 3

array

Question 4

is an array in which all elements are arranged like a list

Answer 4

one-dimensional array

Question 5

The following example of one-dimensional array that can store 10 integers and all the array elements are
initialized to zero

Answer 5

int[] numbers = new int[10];

Question 6

The following example shows how to assign values to individual array elements by using an index number

Answer 6

numbers[0] = 45;
numbers[4] = 23;

Question 7

The example below shows how to initialize an array upon declaration:

Answer 7

double[] grades = { 2.50, 2.75, 1.25, 5.0, 1.50 };

Question 8

in C# is used to process the elements of an array starting with index 0 up to the ending index. T

Answer 8

foreach statement

Question 9

The following example shows how to use a foreach statement to access the all the
elements of the array grades:

Answer 9

foreach (double grade in grades)
{
Console.Write(grade + “ / “);
}
Output:
2.5 / 2.75 / 1.25 / 5 / 1.5 /

Question 10

the array elements are arranged in rows and columns. The elements in this array are arranged in a
tabular form and are therefore stored and accessed by using two (2) indices: one (1) index refers to the row, and the other
refers to the column location.

Answer 10

a two-dimensional array,

Question 11

The following example defines a two-dimensional array consisting of two (2)
rows and four (4) columns:

Answer 11

int[,] table = new int[2, 4];

Question 12

The example below shows how to assign values to individual array elements by specifying the row and column numbers:

Answer 12

table[0, 1] = 18;
table[1, 3] = 4;

Question 13

The following example shows how to initialize a two-dimensional array upon declaration:

Answer 13

int[,] table = {
{ 2, 3 },
{ 12, 5},
{ 3, 8 },
{ 18, 3 }
};

Question 14

The following shows how to access the element of a two-dimensional array:

Answer 14

Console.WriteLine(table[3, 0]); //this prints the 18

Question 15

in C# is a collection that behaves as a dynamic array where the array size can dynamically increase as
required

Answer 15

ArrayList class

Question 16

The ArrayList class is defined in the

Answer 16

System.Collections namespace

Question 17

The following example shows how to create an ArrayList:

Answer 17

ArrayList nameList = new ArrayList();

Question 18

is used to add an element to the list

Answer 18

Add() method

Question 19

The following is the example of adding elements on the ArrayList
named nameList:

Answer 19

nameList.Add(“Jack Paul”);
nameList.Add(“Adrian Castro”);
nameList.Add(“Peter Cruz”);
nameList.Add(“Angela Cruz”);

Question 20

The elements of an ArrayList can be accessed by specifying an integer index. For example:

Answer 20

Console.WriteLine(nameList[2]); //this will print Peter Cruz

Question 21

is used to process all the elements of an ArrayList

Answer 21

The foreach loop

Question 22

Example of foreach loop

Answer 22

foreach (string name in nameList)
{
Console.Write(name + “, “);
}
Output:
Jack Paul, Adrian Castro, Peter Cruz, Angela Cruz

Question 23

is a sequential collection of characters that is used to represent text

Answer 23

string

Question 24

In C#, a string is an object of class string in the

Answer 24

System namespace

Question 25

In C#, a string variable can be initialized by using either of the following:

Answer 25

* directly assigning a string literal; or * using the new keyword and calling the String class constructor.

Question 26

is used to escape characters with special use, such as newline (\n)

Answer 26

the backslash (\)

Question 27

The following statements show an example of how to use new keyword and String class constructor:

Answer 27

char[] word = { 'H', 'e', 'l', 'l', 'o', '!' }; string strGreet = new string(word);

Question 28

This property is used to get the character at a specified index position of a string. For example:

Answer 28

char –

Question 29

This property is used to get the total number of characters in the string. For example

Answer 29

Length –

Question 30

Example for Char:

Answer 30

string word = "Computer"; char letter = word[2]; //the value of variable letter is character 'm'

Question 31

Example for Length

Answer 31

string word = "Computer"; int total = word.Length; //the value of variable total is 8

Question 32

This returns true if the specified substring occurs within the string object; otherwise, it returns false. For example: string sentence = "The quick brown fox jumps."; bool isContain = sentence.Contains("fox"); //returns tru

Answer 32

bool Contains(string value)

Question 33

This determines whether the specified substring has the same value with the string object. The comparisonType parameter specifies the rules to use in comparing strings, such as ignoring the case version of the characters. Example 1: string word = "Computer"; bool isSame = word.Equals("computer", StringComparison.CurrentCulture); //this returns false Example 2: string word = "Computer"

Answer 33

bool Equals(string value, StringComparison comparisonType)

Question 34

This returns the index position value of the first occurrence of the specified character within the string object if that character is found; otherwise, it returns -1 if not found. For example: string word = "Computer"; int index = word.IndexOf('p'); //returns integer 3

Answer 34

int IndexOf(char value)

Question 35

This returns a copy of the string object except that all of the occurrences of an old character are replaced with a new character. For example: string word = "Color"; string strChanged = word.Replace('o', '#'); //returns a copy of string "C#l#r

Answer 35

string Replace(char oldValue, char newValue)

Question 36

This returns a converted copy of object as a string. For example: double value = 105.25; string strValue = value.ToString(); //converted 105.25 into string

Answer 36

string ToString()

Question 37

This returns a copy of the string object converted to lowercase. For example: string word = "COMPUTER"; string strConverted = word.ToLower(); //returns a copy of string "computer"

Answer 37

string ToLower()

Question 38

This returns a copy of the string object converted to uppercase. For example: string word = "computer"; string strConverted = word.ToUpper(); //returns a copy of string "COMPUTER"

Answer 38

string ToUpper()

Question 39

C# provides the ___________ class that represents a mutable string of characters.

Answer 39

StringBuilder

Question 40

represents a mutable string of characters that allows the user to expand the number of characters in the string object without allocating additional memory space.

Answer 40

StringBuilder class r

Question 41

The following shows the way of creating a string using the StringBuilder class and using the new keyword and StringBuilder constructor:

Answer 41

StringBuilder strComputer = new StringBuilder("Computer");

Question 42

to concatenate a string to the string object of StringBuilder class.

Answer 42

Append() method

Question 43

The example below will return the string ("Computer is a great invention.".

Answer 43

strComputer.Append(" is a great invention.");

Question 44

The following example shows how to use these properties:

Answer 44

StringBuilder word = new StringBuilder("Computer"); word[0] = '#'; //change the character at index 0 to '#' for (int index = 0; index < word.Length; index++) { Console.Write(word[index] + " + "); //gets the character at the specified index } Output: # + o + m + p + u + t + e + r +

Question 45

This appends a copy of the specified substring to the StringBuilder object. For example: StringBuilder word = new StringBuilder("Computer"); word.Append(" Ethics"); //returns the string "Computer Ethics"

Answer 45

Append(string value)

Question 46

This returns true if the specified substring is equal to the StringBuilder object; otherwise, it returns false. For example: StringBuilder wordA = new StringBuilder("computer"); StringBuilder wordB = new StringBuilder("computer"); wordA.Equals(wordB); //returns true because same content

Answer 46

Equals(string value)

Question 47

This removes all characters from the current StringBuilder object. For example: StringBuilder word = new StringBuilder("Computer"); word.Clear(); word.Append("Ethics"); //returns the string "Ethics" only

Answer 47

Clear()

Question 48

This replaces all occurrence of a specified old character of the StringBuilder object with a new character. For example: StringBuilder word = new StringBuilder("Color"); word.Replace('o', '*'); //returns the string "C*l*r"

Answer 48

Replace(char oldValue, char newValue)

Question 49

This converts the value of the StringBuilder object to a string. For example: StringBuilder word = new StringBuilder("computer"); string strWord = word.ToString();

Answer 49

ToString()

Question 50

refers to a construct that enables a program to execute a block of statements or a loop body repetitively as long as the defined condition evaluates to true.

Answer 50

loop

Question 51

is used when an operation needs to repeat multiple times

Answer 51

Looping

Question 52

This loop repeats a block of statements as long as a given condition evaluates to true. It evaluates the condition first before executing the loop body

Answer 52

while –

Question 53

This is similar with while loop, except that it executes the block of statements before evaluating the given condition regardless if it evaluates to true or false.

Answer 53

do…while –

Question 54

This loop repeats a block of statement for a specified number of times

Answer 54

for –

Question 55

. The following is the general syntax of while loop in C# including an example:

Answer 55

Syntax: while (condition) { //statements in loop body } For example: //this will print a sequence of numbers from 1 to 10 int start = 1; while (start <= 10) { Console.WriteLine(start); start++; }

Question 56

that is used to control the loop condition

Answer 56

loop control variable

Question 57

Otherwise, the loop body continues to execute endlessly. This is called

Answer 57

infinite loop

Question 58

The following is the general syntax of do…while loop in C# including the example:

Answer 58

Syntax: do { //statements in loop body } while (condition); For example: //this will print a sequence of numbers from 1 to 10 int start = 1; do { Console.WriteLine(start); start++; } while (start <= 10);

Question 59

The for loop in C# takes the following general syntax including an example: riteLine(start); }

Answer 59

Syntax: for (initialization; condition; update) { //statements in loop body } For example: //this will print the numbers from 1 to 10 for (int start = 1; start <= 10; start++) { Console.W

Question 60

The following is the flow of control of a for loop:

Answer 60

1. The initialization step is executed first, and it contains the starting value of the loop. This is executed only once. 2. The defined condition is then evaluated. If it evaluates to false, then the loop terminates and the loop body will not be executed. However, if the condition evaluates to true: Step A. The statements in the loop body is executed. Step B. After executing the loop body, the flow of control jumps up to the update step to update the loop control variable or condition. Step C. The condition is reevaluated. If it evaluates to true, then repeat Step A. However, if it evaluates to false, then the loop execution is terminated.

Question 61

are used to change the flow of control of a looping structure.

Answer 61

Jump statements

Question 62

terminates a loop or a switch statement and transfers the flow of program execution to the statements following the enclosing loop or switch statement

Answer 62

e break

Question 63

The following example shows how to implement a break statement in a loop:

Answer 63

Example: for (int num = 1; num <= 10; num++) { if (num == 5) { break; //if this statement is executed the loop will stop } Console.Write(num + " "); } Output: 1 2 3 4

Question 64

statement is used to skip the remaining statements in the loop body and immediately reevaluates the condition if it’s a while or do…while loop, or it jumps to the update step if it’s a for loop.

Answer 64

e continue

Question 65

The following example shows how to implement a continue statement in a loop:

Answer 65

Example: for (int num = 1; num <= 10; num++) { if (num == 5 || num == 6) { continue; //if this statement is executed it will ignore the print statement below and the execution jumps back to the loop } Console.Write(num + " "); } Output: 1 2 3 4 7 8 9 1

Question 66

are used to execute particular statements whether the value of the given condition evaluates to true or false. These are used to alter the flow of program that willselect a block of statements to execute.

Answer 66

Selection statements or selection structures

Question 67

The C# provides three (3) selection structures:

Answer 67

* The if and if…else statements are conditionalstatements that include a logical expression and provide a one- or two-way selections. * The switch statement executes a block of statements based on the variable to be tested for equality against a list of values

Question 68

instructs the program to execute a certain block of statements only if a particular condition evaluates to true; otherwise, the program will execute the bock of statements in the else statement if false

Answer 68

if statement

Question 69

An if-else statement in C# takes the following syntax and example:

Answer 69

Syntax: if (expression) { //statement(s) } else { //statement(s) } For example: int exam_score = 75; if ( exam_score >= 60 ) { Console.WriteLine("The student passed the exam."); } else { Console.WriteLine("The student failed the exam."); }

Question 70

is used to combine multiple conditions into a single selection structure. This is also called multiple selection

Answer 70

else if statement

Question 71

An else if statement is placed after the if statement or another else if statement. For example:

Answer 71

int exam_score = 75; if (exam_score >= 90) { Console.WriteLine("The grade of the student is A."); } else if (exam_score >= 80) { Console.WriteLine("The grade of the student is B."); } else if (exam_score >= 70) { Console.WriteLine("The grade of the student is C."); } else if (exam_score >= 60) { Console.WriteLine("The grade of the student is D."); } else { Console.WriteLine("The grade of the student is F."); }

Question 72

is used to execute a block of statements based on the variable to be tested for equality against predefined list of values.

Answer 72

switch statement

Question 73

The general syntax of a switch statement in C# is as follows:

Answer 73

switch (variable or expression) { case value1: //statement(s) break; case value1: //statement(s) break; . . . case valuen: //statement(s) break; default: //statement(s) break; }

Question 74

is a special type of decision-making operator used to perform an operation that evaluates a logical expression then selects between two (2) single statements depending on whether the defined expression evaluates to true or false and evaluates it

Answer 74

conditional operator, also called as ternary operator (?:),

Question 75

The general syntax of ternary operator i

Answer 75

condition ? consequence : alternative Example 1: int sum = 4 > 2 ? 4 + 2 : 4 – 2; //the return value is 6 and assigned to the variable sum Example 2: int exam_score = 75; string result = exam_score >= 60 ? "Student passed the exam." : "Student failed the exam."; Console.WriteLine(result)