Why are inline functions used in programming?

Inline functions are used to improve the performance of a program. When a function is declared as inline, the compiler attempts to replace the function call with the body of the function itself at the call site, instead of a normal jump to the function's address.

Advantages of inline functions:

• Reduces overhead costs of function calls (no jump and return).
• Can improve code optimization by the compiler.

However, excessive use of inline can lead to an increase in binary size (code bloat).

In Android (for example, in Kotlin), the keyword inline is often used for higher-order functions to avoid creating additional objects and to improve performance.

Example in Kotlin:

inline fun <T> measureTime(block: () -> T): T {
    val start = System.nanoTime()
    val result = block()
    val end = System.nanoTime()
    println("Time: ${end - start} ns")
    return result
}

Here, the measureTime function will be inlined at the call site, reducing overhead.