Why switch case is faster than if else?

A switch statement is usually more efficient than a set of nested ifs. The compiler can do this because it knows that the case constants are all the same type and simply must be compared for equality with the switch expression, while in case of if expressions, the compiler has no such knowledge.

Similarly, you may ask, which one is faster if else or switch?

General rule is use switch whenever the number of conditions is greater than 3 (for readability). if / else if / else is more flexible (hence better), but switch is slightly faster because it just computes the condition once and then checks for the output, while if has to do this every time.

Similarly, what is the difference between if else and switch case? Key Differences Between if-else and switch The expression inside if statement decides whether to execute the statements inside if block or under else block. On the other hand, the expression inside a switch statement decides which case to execute. You can have multiple if statement for multiple choice of statements.

Beside this, which among switch and if is better and why?

switch statement is better than if-else statement because switch statement takes less time to compile the program. You should use switch statements if you have multiple choices. It also makes your code easier to read.

What are the advantages of switch case?

Advantages:-

Easier to read than equivalent if-else statement.
More efficient than equivalent if-else statement (destination can be computed by looking up in table).
Easier to debug.
Easier to maintain.

23 Related Question Answers Found

Why switch is better than if?

A switch statement is usually more efficient than a set of nested ifs. The compiler can do this because it knows that the case constants are all the same type and simply must be compared for equality with the switch expression, while in case of if expressions, the compiler has no such knowledge.

When would you use a switch case?

Switch statements are far easier to read and maintain, hands down. And are usually faster and less error prone. Use switch every time you have more than 2 conditions on a single variable, take weekdays for example, if you have a different action for every weekday you should use a switch.

What is the purpose of if statement?

The if statement is used to check a condition and if the condition is true, we run a block of statements (called the if-block), else we process another block of statements (called the else-block). The else clause is optional.

Is case more efficient than if?

Case statement is more efficient than if statement but it depends compiler to compiler.

Are switch statements Bad?

Switch case is not a bad syntax, but its usage in some cases categorizes it under code smell. It is considered a smell, if it is being used in OOPS. Thus, Switch case should be used very carefully.

What is the Do While loop syntax?

Syntax. do { statement(s); } while( condition ); Notice that the conditional expression appears at the end of the loop, so the statement(s) in the loop executes once before the condition is tested. If the condition is true, the flow of control jumps back up to do, and the statement(s) in the loop executes again.

What is switch in C?

Switch Statement in C/C++ Switch case statements are a substitute for long if statements that compare a variable to several integral values. The switch statement is a multiway branch statement. It provides an easy way to dispatch execution to different parts of code based on the value of the expression.

What is switch statement example?

A switch statement tests the value of a variable and compares it with multiple cases. Once the case match is found, a block of statements associated with that particular case is executed. Each case in a block of a switch has a different name/number which is referred to as an identifier.

Can Break be used in if statement?

There is a "break" statement used to terminate loops early and are typically inside of "if" statements, but you can't break out of an if, it only terminates loops like for, while and repeat. The return statement can be used to terminate a function early.

What are the limitations of switch statement?

Disadvantages of switch statements

float constant cannot be used in the switch as well as in the case.
You can not use the variable expression in case.
You cannot use the same constant in two different cases.
We cannot use the relational expression in case.

How does a switch statement work?

A statement in the switch block can be labeled with one or more case or default labels. The switch statement evaluates its expression, then executes all statements that follow the matching case label. Technically, the final break is not required because flow falls out of the switch statement.

Why do we use network switches?

A switch is used in a wired network to connect to other devices using Ethernet cables. The switch allows each connected device to talk to the others. Switches allow communication (within your network) that's even faster than the Internet. High-end switches can be tailored to your network needs with pluggable modules.

What is nested IF statement?

A nested if in C is an if statement that is the target of another if statement. Nested if statements means an if statement inside another if statement. Yes, both C and C++ allows us to nested if statements within if statements, i.e, we can place an if statement inside another if statement.

What is a switch in C++?

C++ switch statement. Advertisements. A switch statement allows a variable to be tested for equality against a list of values. Each value is called a case, and the variable being switched on is checked for each case.

How many cases a switch statement can have?

Standard C specifies that a switch can have at least 257 case statements. Standard C++ recommends that at least 16,384 case statements be supported! The real value must be implementation dependent.

Why do we use switch case?

Switch statements are used when you clearly know what are possible values for the condition variable. Each value in that list of possible value is called case. When the value given in input matches the value in the case statement, the block of code below case gets executed until it reaches the break statement.

What is a ternary expression?

The ternary operator is an operator that takes three arguments. The first argument is a comparison argument, the second is the result upon a true comparison, and the third is the result upon a false comparison. If it helps you can think of the operator as shortened way of writing an if-else statement.