Go - (5) Errors & Loops

Error Handling

• Languages like JS use try catch blocks for error handling.
• But in Go, it is a bit different.

Check the example below.

func getUser() (string, error) {
// ... some code here
    return username, err
}

func main() error {
    name, err := getUser()
    if err != nil {
// if err is not nil, return the error
        return err
    }
// if no errors, print the username
    fmt.Printf("User name: %s", name)
}

• Error handling in Go is more convenient because it doesn't need nested error handling like in try-catch blocks.
• Also, we can see which functions return error by looking at the function signature.
• Go has a package named errors. It has methods like New() to initialize errors.

import (
    "errors"
)

func getUser() (string, error) {
// ... some code here
    return username, errors.New("couldn't get the username") // a new err is returned
}

Loops

The syntax of Go loops is very similar to loops in JS. The only difference is that we don't use parentheses.

An example of a traditional for loop is given below.

for i := 0; 0 < 10; i++ {
    fmt.Print(i)
}

I Go loops, the condition in the loop is optional. If you check the example below, it goes out of the loop considering the conditional block.

totalCost := 0.0
threshold := 5.0
for i := 0; ; i++ {
    totalCost += 1.0 + (0.01 * float64(i))
    if totalCost > threshold {
        return i
    }
}

---