Boost Your Program’s Performance: 7 Techniques for Optimal Code Optimization

Ikedinma Ugochukwu
6 min readApr 1, 2023

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A laptop with a cup and flower base on a table
Photo by Clément Hélardot on Unsplash

I recently read an article talking about how they do things in an organization and something caught my attention, it was that no code is being approved until it has been fully optimized, so that got me thinking what is code optimization? and how can I optimize my own code?

What is code optimization?

Code optimization is the process of improving the performance of a computer program or software by making changes to the code to reduce the time and resources it takes to execute. The goal of code optimization is to make a program run faster, use less memory, or consume fewer system resources while still producing the same output.

What are the ways a piece of code can be optimized?

There are several ways a piece of code can be optimized. Here are some common techniques that programmers use to optimize code:

  • Reduce the number of operations: Look for opportunities to eliminate redundant or unnecessary operations. For example, you can replace multiple calculations with a single calculation, or simplify complex expressions.
An example of a complex expression code
An example of a simplified complex expression code

In this example, the original expression combines multiple arithmetic operations and parentheses, making it hard to read and understand. By breaking the expression down into smaller parts and using descriptive variable names, the code becomes more readable and easier to maintain.

Additionally, by splitting the expression into two parts, we can reduce the number of calculations and make the code more efficient. The numerator is calculated only once, instead of twice in the original expression, which could result in performance improvements for large data sets.

  • Use better data structures: Choosing the right data structure can significantly improve the performance of a program and improve the overall efficiency of the code. Choosing the right data structure can be tasking but there are courses out there that can help our decision making to become better.
  • Optimize loops: Loops can be a major bottleneck in a program. To optimize loops, you can reduce the number of iterations, use loop unrolling, or reorder the loop to improve cache locality.
A code showing an unoptimized way of writing a loop
A code showing a way of writing an optimized loop

In this example, the original loop iterates over an array using the length property of the array in the loop condition. This means that the length property is accessed and evaluated for each iteration of the loop. However, since the length of the array doesn’t change during the loop, we can store the length in a constant variable before the loop to reduce the number of times it is accessed.

By storing the array length in a constant variable, we avoid having to re-evaluate the length property on each iteration of the loop, which can improve performance, especially for large arrays. This optimization technique is known as loop-invariant code motion, and it’s a common optimization strategy used to reduce the overhead of loops.
Basically, any value evaluated which is a constant can be stored in a variable and accessed from the variable to make the code more efficient.

  • Minimize function calls: Function calls come with an overhead cost. To optimize code, you can reduce the number of function calls by inlining functions, using function pointers, or creating macros.
A code showing how to call a function in an unoptimized way
A code showing an in-line function call

In this example, the original code defines a square function to calculate the square of a number and a calculateArea function that calls the square function twice to calculate the area of a rectangle.

By inlining the square function and multiplying the width and height directly, we can eliminate the overhead of the function call and return operations. This can simplify the code and improve performance, especially for simple functions that are called frequently.

Note that inlining functions can make the code harder to read and maintain, especially for complex functions. It’s important to balance the benefits of inlining with the readability and maintainability of the code.

  • Optimize memory usage: Memory usage can also be a significant bottleneck in a program. To optimize memory usage, you can reduce the number of memory allocations, reuse memory, or use memory pools.
A code that specifies an array size before the array is being filled

In this example, we create a large array of size 1000000 and fill it with random numbers using a for loop. By creating the array with the new keyword and specifying the size upfront, we enforce memory allocation and avoid dynamic resizing of the array during the loop, which can be expensive in terms of performance.

Enforcing memory allocation can help optimize code that relies heavily on arrays or other data structures, especially for performance-critical applications. However, it’s important to be mindful of the memory usage and avoid unnecessary allocations to prevent memory leaks or other performance issues.

  • Use compiler optimizations: Most modern compilers have built-in optimization features that can automatically optimize code. To take advantage of these features, you can use compiler flags or annotations to inform the compiler of the optimization goals.

In the example above, we’re using the “use strict” directive to enable strict mode, which can help the compiler optimize the code and improve error handling. We’re also using JSDoc annotations to provide more information about the function and its parameters.

The “@optimize {inline}” annotation tells the compiler that we want the function to be inlined, which means that the function code will be replaced with the function call in the compiled output. This can help reduce the function call overhead and improve performance.

Overall, by using compiler flags and annotations like these, we can help the JavaScript compiler optimize our code and improve its performance.

  • Parallelize the code: Multi-threading and parallel processing can significantly improve the performance of a program. To parallelize code, you can use threading libraries or parallel programming models such as OpenMP or MPI. In JavaScript, parallelization can be achieved using web workers or libraries like parallel.js. Here’s an example of a JavaScript code that is parallelized using parallel.js:
A code that has been paralelized using the parallel.js library in JavaScript

In this example, we define a function called heavyTask that performs a CPU-intensive task (in this case, a loop that calculates the sum of random numbers). We then create an array of tasks with different input sizes and pass it to a new Parallel object from the parallel.js library.

We then call the spawn method on the Parallel object and pass the heavyTask function as a callback. The spawn method runs the heavyTask function on each element of the tasks array in parallel using multiple threads or processes, depending on the environment.

Finally, we set up a callback function to handle the results of the parallel execution and log the results.

These are just some of the many techniques that can be used to optimize code. The optimal approach will depend on the specific requirements of the program and the resources available.

My summary is code optimization is an essential part of software development, especially for large-scale applications where performance and efficiency are critical. By optimizing the code, programmers can improve the user experience, reduce hardware costs, and increase the scalability of the software. Hopefully when writing your next code, you will keep this at the back of your mind.

Let me know what you think of this in the comment section and if you like what you just read, please follow me for more content.

Thank you for reading (•‿•)

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Ikedinma Ugochukwu

Ugo is a passionate developer with a deep interest in web development and machine learning. Follow Ugo to stay updated on their latest articles and musings.