withTimeout and withTimeoutOrNull

Two Timeout Functions

Function	On timeout
`withTimeout(ms) { }`	throws `TimeoutCancellationException`
`withTimeoutOrNull(ms) { }`	returns `null`

Example

import kotlinx.coroutines.*

suspend fun fetchQuote(ms: Long): String {
    delay(ms)
    return "RELIANCE: 2941.50"
}

fun main(): Unit = runBlocking {
    val fast = withTimeoutOrNull(300) { fetchQuote(100) }
    println("Fast call: $fast")

    val slow = withTimeoutOrNull(300) { fetchQuote(1000) }
    println("Slow call: ${slow ?: "timed out, showing cached price"}")

    try {
        withTimeout(200) { fetchQuote(1000) }
    } catch (e: TimeoutCancellationException) {
        println("withTimeout threw: ${e.message}")
    }
}

Output

Fast call: RELIANCE: 2941.50
Slow call: timed out, showing cached price
withTimeout threw: Timed out waiting for 200 ms

Tip: TimeoutCancellationException is a subclass of CancellationException. If you call withTimeout inside a launch and do not catch it, the coroutine is just silently cancelled. Prefer withTimeoutOrNull when you want a fallback.