What are the differences between Dispatchers.IO and Dispatchers.Default in Coroutine, and in which cases is it preferable to use them?

Dispatchers.IO and Dispatchers.Default are standard coroutine dispatchers in Kotlin, designed for different types of tasks.

• Dispatchers.IO is optimized for input/output (I/O) operations, such as reading/writing files, network requests, working with databases. It uses a thread pool that can expand as needed to avoid blocking the main thread.

• Dispatchers.Default is intended for CPU-intensive tasks, such as computations, data processing, complex algorithms. It uses a thread pool usually equal to the number of available processor cores.

When to use:

• Use Dispatchers.IO for operations related to input/output that may block the thread.
• Use Dispatchers.Default for heavy computational tasks to avoid blocking the main thread and to efficiently utilize the CPU.

Example:

// Reading a file — IO task
withContext(Dispatchers.IO) {
    val data = file.readText()
}

// Processing data — CPU task
withContext(Dispatchers.Default) {
    val result = heavyComputation()
}