3. • In programming, a switch, case, select or inspect
statement is a type of selection control mechanism
that exists in most imperative programming languages
such as Pascal, Ada, C/C++, C# programming language ,
Java, and so on. It is also included in several other
types of programming languages. Its purpose is to
allow the value of a variable or expression to control
the flow of program execution via a multiway branch
(or "goto", one of several labels). The main reasons for
using a switch include improving clarity, by reducing
otherwise repetitive coding, and (if the heuristics
permit) also offering the potential for faster execution
through easier compiler optimization in many cases.
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4. • switch (n)
• {
• C# • case 0:
• • Console.WriteLine("You typed zero.");
• break;
• In C# programming, every case block • case 1:
that contains any statements must • case 4:
• case 9:
have a reachable end point, or • Console.WriteLine("n is a perfect square.");
triggers a compilation error.In • break;
• case 2:
programming usually, this is a break • Console.WriteLine("n is an even number.");
statement, but any jump statement • goto case 3;
can be used – such as return, goto or • case 3:
• case 5:
throw – or the switch can simply end • case 7:
with an infinite loop. Case fall- • Console.WriteLine("n is a prime number.");
through is only permitted when there • break;
• case 6:
are no statements between one case • case 8:
statement and the next. If fall- • Console.WriteLine("n is an even number.");
• break;
through is otherwise desired, it must • default:
be made explicit with the goto case • Console.WriteLine("Only single-digit numbers are
allowed.");
construct. C# programming also • break;
allows the use of non-integer case • }
values, such as Strings.
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5. • Select Case n
• Case Is < -5
• MsgBox("n is less than -5")
• Visual Basic .NET • Case -4 To -1
•
• •
MsgBox("n is between -4 and -1")
Case 0
• In programming, Visual Basic • MsgBox("n is 0")
• Case 2, 4, 6, 8
.NET, the switch statement is • MsgBox("n is even")
called "Select Case • Case 1, 3, 5, 7, 9
programming", and fall-through • MsgBox("n is odd")
• Case Else
to later blocks is not supported. • MsgBox("only single-digit numbers are allowed.",
However, ranges and various vbCritical)
• End Select
constructs from If statements are •
both supported • Visual FoxPro
•
• Visual FoxPro:
•
• Do Case
• Case field_1 = "X"
• Replace field_b With 1
• Case field_1 = "Y"
• Replace field_b With 2
• Case field_1 = "Z"
• Replace field_b With 3
• Endcase
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6. • Haskell
• (f:r) -> "Not empty, first item is " ++ show f
• [] -> "List is empty!"
• Haskell's case construct, unlike C- •
• OCaml, F#
influenced programming •
languages, has no fall-through • OCaml and F#'s match construct is like
behaviour. It is a programming Haskell's case above.
expression which returns a value, •
and it can deconstruct values • (* OCaml *)
using pattern matching. • match list with
• f::r -> "Not empty, first item is " ^
string_of_int f
• | [] -> "List is empty!"
•
• // F#
• match list with
• | f::r -> "Not empty, first item is " + string f
• | [] -> "List is empty!"
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7. • Pascal • case age of
• 0,1: writeln('baby');
• In Programming, Pascal • 2,3,4: writeln('toddler');
does not allow “fall • 5..12: writeln('kid');
through”, but has ranges • 13..19: writeln('teenager');
and comma separated • 20..25: writeln('young');
literal lists. • else writeln('old');
• end;
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8. • Perl • use feature 'switch';
• • given ($foo) {
• when (undef) {
• Perl 5.10 has a powerful built in switch
• say '$foo is undefined';
statement called given, where the
• }
programming cases are called when:
• when ("foo") {
• say '$foo is the string "foo"';
• }
• when ([1,3,5,7,9]) {
• say '$foo is an odd digit';
• continue; # Fall through
• }
• when ($_ < 100) {
• say '$foo is numerically less than 100';
• }
• when (&complicated_check) {
• say 'a complicated check for $foo is true';
• }
• default {
• die "I don't know what to do with $foo";
• }
• }
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11. • In programming, very often when you write code, you want
the same block of code to run a number of times. You can use
looping statements in your code to do this.
•
• In programming, the JavaScript programming have the
following looping statements:
•
• While programming- loops through a block of code while a
condition is true
• Do...while programming- loops through a block of code once,
and then repeats the loop while a condition is true
• For programming- run statements a specified number of times
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12. • while • while (condition)
• • {
• In programming while • code to be executed
statement will execute a • }
block of code while a •
condition is true..
•
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13. • Do...while • do
• • {
• In Programming the do...while • code to be executed
statement will execute a block • }
of code once, and then it will • while (condition)
repeat the loop while a
condition is true
•
• The Java programming
language also provides a do-
while statement, which can be
expressed as follows:
•
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14. • for • for (initialization;
• condition; increment)
• In programming the • {
“for” statement will • code to be executed
execute a block of code • }
a specified number of
times
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15. • if (expression)
• statement;
•
• or
•
• if (expression)
• {
• Block of statements;
• }
• If statement •
• or
•
• if (expression)
• {
• Block of statements;
• }
• In Programming, It takes an
• else
• {
• Block of statements;
expression in parenthesis •
•
}
and an statement or block of •
•
or
statements. if the expression •
•
if (expression)
{
is true then the •
• }
Block of statements;
programming statement or •
•
else if(expression)
{
block of statements gets •
• }
Block of statements;
executed otherwise these •
•
else
{
statements are skipped. •
• }
Block of statements;
•
• ? : Operator
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16. • While Loop • #include
•
• In programming, For repeating C • int main(void)
programming statements whiles • {
a condition is true,the while •
provides a the necessary • int loop = 0;
mechanism. •
• while (loop <=10)
• {
• printf(“%d”, loop);
• ++loop
• }
•
• return 0;
•
• }
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17. • Input : In any programming language input
means to feed some data into program.
Programming can be given in the form of file or
from command line. C programming language
provides a set of built-in functions to read given
input and feed it to the program as per
requirement.
•
• Output : In any programming language output
means to display some data on screen, printer or
in any file. C programming language provides a
set of built-in functions to output required data.
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