Panic behavior in Go - Mini Project: Build & Apply

Panic behavior

📖 Scenario: Imagine you are writing a simple Go program that processes user input. Sometimes, the input might cause unexpected errors. Go uses panic to stop the program immediately when something goes wrong.

🎯 Goal: You will create a Go program that demonstrates how panic works by intentionally causing a panic and then recovering from it using defer and recover.

📋 What You'll Learn

Create a function called causePanic that triggers a panic with the message "Something went wrong!".

Create a function called handlePanic that uses defer and recover to catch the panic and print "Recovered from panic: " followed by the panic message.

Call handlePanic and then causePanic inside the main function.

Print "Program continues after panic recovery." after calling causePanic.

💡 Why This Matters

🌍 Real World

In real Go programs, panic and recover help handle unexpected errors like file read failures or invalid data, allowing programs to clean up and continue safely.

💼 Career

Understanding panic behavior is important for Go developers to write robust, fault-tolerant applications that can handle errors without crashing unexpectedly.

1

Create the causePanic function

Write a function called causePanic that triggers a panic with the message "Something went wrong!" using panic("Something went wrong!").

Go

package main

func causePanic() {
    // Your code here
}

func main() {

}

Hint

Use the panic function inside causePanic to stop the program with the given message.

2

Create the handlePanic function with defer and recover

Write a function called handlePanic that uses defer to call an anonymous function. Inside the anonymous function, use recover() to catch the panic. If a panic is caught, print "Recovered from panic: " followed by the panic message using println.

Go

package main

func causePanic() {
    panic("Something went wrong!")
}

func handlePanic() {
    // Your code here
}

func main() {

}

Hint

Use defer to delay the anonymous function until handlePanic returns. Inside it, use recover() to catch the panic value.

3

Call handlePanic and causePanic inside main

Inside the main function, first call handlePanic() and then call causePanic().

Go

package main

func causePanic() {
    panic("Something went wrong!")
}

func handlePanic() {
    defer func() {
        if r := recover(); r != nil {
            println("Recovered from panic: ", r)
        }
    }()
}

func main() {
    // Your code here
}

Hint

Call handlePanic() before causePanic() in main to catch the panic.

4

Print a message after panic recovery

After calling causePanic() in main, add a println statement that prints "Program continues after panic recovery.".

Go

package main

func causePanic() {
    panic("Something went wrong!")
}

func handlePanic() {
    defer func() {
        if r := recover(); r != nil {
            println("Recovered from panic: ", r)
        }
    }()
}

func main() {
    handlePanic()
    causePanic()
    // Your code here
}

Hint

Use println("Program continues after panic recovery.") after causePanic() in main.