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C++ Provides a multiple branch selection called as switch. This selection statement succesively test against a list of integer or character constants. When a match is found the statements associate with constants are executed.
When no match is found default statement is used.
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What is the use of the default case in a switch case?
The default case in a switch statement will be activated if none of the other case values match. It is used exactly for this purpose - if nothing else matches in the switch then this one will always match.Without a default case value, if nothing matched in the switch then nothing will be done. Sometimes it is necessary to know that nothing matched.
How do you use logic inside switch statement?
Nothing special, eg:switch (c) {case 'A':/* use any 'logic' you want */break;default:/* use any 'logic' you want */}
What is the syntax and purpose of the switch statement in c plus plus?
The purpose of a switch statement is to execute one of several sections of code, depending on the value of an integral expression. The syntax of a switch statement can be stated as follows: switch(expression) { case(constant_expression_1): statement case(constant_expression_2): statement //.. case(constant_expression_n): statement [default: statement] } The ellipses around the constant expressions are optional and may be omitted. The switch statement body consists of one or more case labels and an optional default label (the case labels are also optional, but a switch statement would be meaningless without them). The default statement, if present, need not be the final label in a switch statement. Case and default labels may not appear outside of a switch statement, as they are not treated the same as goto labels. The constant_expression in each case label is converted to the type of the switch expression and is compared with the switch expression for equality. Control is immediately passed to the labelled statement whose constant_expression matches the value of the switch expression. Once a label gains control, execution proceeds from that point on and is not impeded by any subsequent case or default labels. However, a break statement may be used to interrupt execution at any time, which will transfer control to the statement immediately following the switch statement body. You may also use a return statement to return control to the calling function, or a goto statement. However, note that while a goto label is not the same as a case label, you may use goto labels inside a switch statement if required. Here's an example demonstrating how code flows through a switch statement: int x; switch(x=rand()%10) // x is a random number in the range 0 to 9. { case(0): x=42; break; case(1): case(2): x=33; break; case(3): x=100; default: x=0; } If x were 0, then execution passes to case(0) where the value 42 is assigned to x and the switch exits. If x were 1 or 2, then 33 is assigned to x and the switch exits. If x were 3, 100 is assigned to x. In all other cases, 0 is assigned to x. You will note that when the switch statement ends, x can only ever be 42, 33 or 0. Why not 100? Look again and you will see that case(3) has no break statement (just as case(1) has no break statement). So although 100 is assigned to x in case(3), the default case immediately assigns 0 to x. This is not a particularly useful switch statement, but it serves to demonstrate how code flows through a switch statement, and how forgetting to put a break statement at the end of a case can cause unexpected errors to creep into your code. While you could emulate the same results using a series of if, else if and else statements, the benefit of a switch statement is that it will generally simplify the complexity of your code, because there is only one expression to evaluate, rather than a series of boolean expressions. Your compiler will generate machine code just as if you'd used a series of if statements, but the switch statement gives a greater sense of structure to the statement, and gives a greater degree of control over which section(s) of code will execute for any given evaluation. And just as ifs can be nested within other ifs, switch statements can be nested within other switch statements. Note that all code in a switch statement must be reachable (that is, not bypassed by all execution paths). For instance the following contains both unreachable and undefined code: switch(x) { x=42; //unreachable case(100): int y=42; break; default: x=y; // y is undefined } The line x=42 cannot be reached because execution must either pass to either the case(100) or the default label. Similarly, the x=y line is invalid because y is defined within the case(100) label, which is not reachable from within the default label due to the break statement.
What is the use of default keyword?
default is used with (switch statement) to handle what'll happen if non of the defined cases happened. ex: int x=4; switch(x) { case 1: cout<<"1"; break; case 2: cout<<"2"; break; case 3: cout<<"3"; break; default : cout<<"It's not 1 or 2 or 3 ..! "; } in that case .. we'll see (It's not 1 or 2 or 3 ..!)
The break statement is required in the default case of a switch selection structure?
Ends the case statement. Without it, any code after where the break; is supposed to be will get executed as well until it does encounter a break; or the end of the switch.Code Example:char cTest = 'a';switch(cTest) {case 'a':/* Code here gets executed. */case 'b': //* Code here gets executed. */case 'c':/* Code here gets executed. */break;case 'd':/* Code here won't be executed. */default:/* Code here won't be executed. */}
What is the use of the default case in a switch case?
The default case in a switch statement will be activated if none of the other case values match. It is used exactly for this purpose - if nothing else matches in the switch then this one will always match.Without a default case value, if nothing matched in the switch then nothing will be done. Sometimes it is necessary to know that nothing matched.
Which statement should you use if you have multiple conditions to check for the same variable?
SWITCHswitch( yourVar ){case 'A':foo++;case 'a':bar++;default :baz++;}The switch statement will only work with integer or character variables, however. If your variable is not of that simple type, then the switch statement will not work. In that case you need to use the standard if-then-else-if sequencing.
How do you use logic inside switch statement?
Nothing special, eg:switch (c) {case 'A':/* use any 'logic' you want */break;default:/* use any 'logic' you want */}
Why break statement is optional in c plus plus?
You use a break statement to end execution of the enclosing iterator (loop) or switch statement. If omitted at the end of a case label, execution continues to the next case label, including the default case, until a jump statement is encountered (break, goto or return) or the switch statement falls from scope. Sometimes this can be desirable behaviour, thus the use of break is optional. A break statement is always optional at the end of the default case, or the last case label. Its usage in loops is always optional, to allow a loop to end prematurely regardless of the conditional expression that controls the loop.
What is the syntax and purpose of the switch statement in c plus plus?
The purpose of a switch statement is to execute one of several sections of code, depending on the value of an integral expression. The syntax of a switch statement can be stated as follows: switch(expression) { case(constant_expression_1): statement case(constant_expression_2): statement //.. case(constant_expression_n): statement [default: statement] } The ellipses around the constant expressions are optional and may be omitted. The switch statement body consists of one or more case labels and an optional default label (the case labels are also optional, but a switch statement would be meaningless without them). The default statement, if present, need not be the final label in a switch statement. Case and default labels may not appear outside of a switch statement, as they are not treated the same as goto labels. The constant_expression in each case label is converted to the type of the switch expression and is compared with the switch expression for equality. Control is immediately passed to the labelled statement whose constant_expression matches the value of the switch expression. Once a label gains control, execution proceeds from that point on and is not impeded by any subsequent case or default labels. However, a break statement may be used to interrupt execution at any time, which will transfer control to the statement immediately following the switch statement body. You may also use a return statement to return control to the calling function, or a goto statement. However, note that while a goto label is not the same as a case label, you may use goto labels inside a switch statement if required. Here's an example demonstrating how code flows through a switch statement: int x; switch(x=rand()%10) // x is a random number in the range 0 to 9. { case(0): x=42; break; case(1): case(2): x=33; break; case(3): x=100; default: x=0; } If x were 0, then execution passes to case(0) where the value 42 is assigned to x and the switch exits. If x were 1 or 2, then 33 is assigned to x and the switch exits. If x were 3, 100 is assigned to x. In all other cases, 0 is assigned to x. You will note that when the switch statement ends, x can only ever be 42, 33 or 0. Why not 100? Look again and you will see that case(3) has no break statement (just as case(1) has no break statement). So although 100 is assigned to x in case(3), the default case immediately assigns 0 to x. This is not a particularly useful switch statement, but it serves to demonstrate how code flows through a switch statement, and how forgetting to put a break statement at the end of a case can cause unexpected errors to creep into your code. While you could emulate the same results using a series of if, else if and else statements, the benefit of a switch statement is that it will generally simplify the complexity of your code, because there is only one expression to evaluate, rather than a series of boolean expressions. Your compiler will generate machine code just as if you'd used a series of if statements, but the switch statement gives a greater sense of structure to the statement, and gives a greater degree of control over which section(s) of code will execute for any given evaluation. And just as ifs can be nested within other ifs, switch statements can be nested within other switch statements. Note that all code in a switch statement must be reachable (that is, not bypassed by all execution paths). For instance the following contains both unreachable and undefined code: switch(x) { x=42; //unreachable case(100): int y=42; break; default: x=y; // y is undefined } The line x=42 cannot be reached because execution must either pass to either the case(100) or the default label. Similarly, the x=y line is invalid because y is defined within the case(100) label, which is not reachable from within the default label due to the break statement.
How if else if statement is differ from switch in general in java?
An else statement is comparing to items, while a switch statement is used to compare multiple items. So if you need multiple results from one statement use a switch but for booleans or very specific functions use a if else statement. Else If ex. if(a=6){System.out.println("It is six");} else(){System.out.println("It is not six");} Switch ex. switch(a){ case 1: System.out.println("it is one"); break; case 2: System.out.println("it is two"); break; default: System.out.println("it is not one or two"); break; } Basically a switch is a good way to check against a lot of possibilities.
What is the use of switch statement in java?
In java, a switch statement is used to simplify a long list of 'if' statements. A switch statement takes the form of:switch (variableName){case condition1; command1;case condition2; command2;...}
The break statement is required in the default case of a switch selection structure?
Ends the case statement. Without it, any code after where the break; is supposed to be will get executed as well until it does encounter a break; or the end of the switch.Code Example:char cTest = 'a';switch(cTest) {case 'a':/* Code here gets executed. */case 'b': //* Code here gets executed. */case 'c':/* Code here gets executed. */break;case 'd':/* Code here won't be executed. */default:/* Code here won't be executed. */}
What is the use of default keyword?
default is used with (switch statement) to handle what'll happen if non of the defined cases happened. ex: int x=4; switch(x) { case 1: cout<<"1"; break; case 2: cout<<"2"; break; case 3: cout<<"3"; break; default : cout<<"It's not 1 or 2 or 3 ..! "; } in that case .. we'll see (It's not 1 or 2 or 3 ..!)
What is switch case?
switch (expression){case constant-value1:statementsbreak [optional];case constant-value2:statementsbreak [optional];...default:statements;}
How do you use a switch statement in GML?
Switch Statements are used to generate different outputs of code based on the value of an expression. Switch Statements work as follows:{randomNumber = floor(random(3))+1;switch(randomNumber) {case 1: { } break;case 2: { } break;case 3: { } break;default: { } break;}}This may seem confusing if you are new to GML, so I will give an in-depth explanation. The first line sets the variable randomNumber to a random number between 0 and 2, and adds it by 1 to make it a random number from 1-3. So far the only thing that has gone on in the code is to set a variable to either 1, 2, or 3. This is where the switch statement comes in.switch(randomNumber) {case 1: { } break;case 2: { } break;case 3: { } break;default: { } break;}this is the actual switch statement. You may be wondering what the case statements are for. case statements are always written inside switch statements and do nothing anywhere else. case statements activate when the expression in the switch statement is the same as the value that they are assigned to. Take a look at this switch statement:{rand = floor(random(3));switch(rand) {case 0: {show_message("The Random Value Was 0");} break;case 1: {show_message("The Random Value Was 1");} break;case 2: {show_message("The Random Value Was 2");} break;}} When the values assigned to the case statements are equal to the expression in the switch statement, the case statement will run the code contained in it's brackets. break statements order the switch statement to abort. The reason that you need break statements inside a switch statement is because it keeps the other cases from activating as well. (When one case statement activates, the others do as well.)A final briefing on switch statements is that they are not limited to variables. Take a look at this switch statement.{switch(obj_block.x > x) {case true: {show_message("The Block Is Ahead Of You.");} break;case false: {show_message("You Are Ahead Of The Block.");} break;}} This switch statement returns a true or false value, and the case statements operate accordingly.
How can you write a Algorithm using switch case in C language with examples?
A switch is a selection statement. We don't use switch statements to create algorithms, although they can form part of an algorithm. The controlling expression must evaluate to a value of integral type or an enum. We can then define case labels for some or all possible evaluations of the control expression. If required, we can define a default label to catch any and all values not explicitly labelled. Upon evaluating the expression, if there is no corresponding case label, control passes to the next statement after the switch statement. Otherwise, control immediately passes to the corresponding case label and execution continues from there until a break, return or goto statement is encountered. If there is no break, return or goto statement before the next case label is encountered, execution "falls through" to the next case. When using fall through, the order of labels is important. Notably, the default label (if any) need not be the final label.
