`else if` vs. `switch() case`: Which Offers Better Performance for Multiple Conditions?

else if and switch() case: Performance comparison of multi-conditional statements

Both

else if and switch() case statements are used to control the flow of program execution based on multiple conditions. However, is one method faster than the other? This article will explore this.

Performance comparison

Typically, for a small number of conditions (usually less than 5), the performance difference between else if and switch() case is negligible. However, when dealing with a large number of conditions, performance optimization is crucial.

switch() case Optimization

The compiler optimizes the switch() case statement in two main ways:

• Lookup table or hash table: For large numbers of conditions (usually more than 5), switch() case is implemented using a lookup table or hash table. This ensures that all conditions have the same access time regardless of their location.
• Jump table optimization: In some cases, the compiler can generate a jump table that directly maps each condition to its corresponding block of code. This avoids sequential evaluation of conditions, significantly improving performance.

else if Disadvantages of the statement

In contrast, the else if statement performs a sequential linear search for all conditions. As the number of conditions increases, the search time also increases linearly, resulting in performance degradation.

Suggestion

For programs containing a large number of conditions, it is recommended to convert else if statements into switch() case statements for performance optimization. A lookup table or hash table implementation ensures efficient access and execution of the appropriate code block based on input conditions.

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