Difference Between if-else and switch

“If-else” and “switch” both are selection statements. The selection statements, transfer the flow of the program to the particular block of statements based upon whether the condition is “true” or “false”.

The fundamental difference between if-else and switch statements is that the if-else statement “selects the execution of the statements based upon the evaluation of the expression in if statements”. The switch statements “selects the execution of the statement often according to a keyboard command”.

Content: if-else Vs switch

1. Comparison Chart
2. Definition
3. Key Differences
4. Conclusion

Comparison Chart

Basis for Comparison	if-else	switch
Basic	Which statement will be executed depend upon the output of the expression inside if statement.	Which statement will be executed is decided by user.
Expression	if-else statement uses multiple statement for multiple choices.	switch statement uses single expression for multiple choices.
Testing	if-else statement test for equality as well as for logical expression.	switch statement test only for equality.
Evaluation	if statement evaluates integer, character, pointer or floating-point type or boolean type.	switch statement evaluates only character or integer value.
Sequence of Execution	Either if statement will be executed or else statement is executed.	switch statement execute one case after another till a break statement is appeared or the end of switch statement is reached.
Default Execution	If the condition inside if statements is false, then by default the else statement is executed if created.	If the condition inside switch statements does not match with any of cases, for that instance the default statements is executed if created.
Editing	It is difficult to edit the if-else statement, if the nested if-else statement is used.	It is easy to edit switch cases as, they are recognized easily.

Definition of if-else

The if-else statements belong to selection statements in OOP. The general form of the if-else statements is as follow

if (expression){
statement(s)
}else{
statement(s)
}

where “if” and “else” are the keywords, and the statements can be a single statement or a block of statements. The expression evaluates to be “true” for any non-zero value and for zero it evaluates to be “false”.

The expression in if statement can contain an integer, character, pointer, floating-point or it can be a boolean type. The else statement is optional in an if-else statement. If the expression returns true, the statements inside if statement is executed, and if it returns false the statements inside else statement are executed and, in case an else statement is a not created no action is performed, and the control of the program jump out of an if-else statement.

Example

Lets us understand with an example.

int i=45, j=34;
if (i==45 & j==34){
cout<< " i ="<<i;
}else{
cout<< " j ="<<j;
}

//output
i=45

Here, the if statement evaluates the equality along with the logical evaluation. If the expression would have return false, then the statement in an else statement would have been executed.

Definition of switch

The switch statements is a multiple-choice selection statement. The general form of the switch statement is as follow

switch( expression ){
case constant1:
statement(s);
break;
case constant2:
statement(s);
break;
case constant3:
statement(s);
break;
.
.
default
statement(s);
}

Where the expression evaluates an integer or character constants. The expression here only evaluates for equality. The expression is verified against the constants present in the case statements. If a match is found, the statements associated with that case is executed, until a “break” occurs. As the break statement is optional in the case statements, if the break statement is not present then, the execution does not stop until the end of the switch statement.

The expression only contains a single expression. The switch statement often uses a keyboard command to choose one among the multiple case statements.

int c;
cout<<" choose the value from 1 to 3"; cin>>i;
switch( i ){
case 1:
cout<<"you choose dark choclate";
break;
case 2:
cout<<"you choose candy";
break;
case 3:
cout<<"you choose lollypop";
break;
.
.
default
cout<<"you choose nothing";
}

Here, the value of “i” will decide which case is to be executed, if a user gives the value of “i” other than 1, 2, or 3, then the default case is executed.

Conclusion

The switch statement is easy to edit as it has created the separate cases for different statements whereas, in nested if-else statements it becomes difficult to identify the statements to be edited.