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| title | date | tags | excerpt | ||
|---|---|---|---|---|---|
| Learning Go: Day Three | 2024-05-03T08:00:00.0Z |
|
For my third day of learning Go, I'm going to take a look at some control structures |
Over the last two days I've learned how to setup and create a Go project, and then how to organise code into packages. I realise I've skipped a crucial step there, though, which is learning how to deal with control structures.
By control structures, I'm referring to things like for- loops, if statements, etc. You know, the things that make the software do things beyond just multiplying 2 by 5.
For-loops
The old trusty workhorse of any programming language. These seem pretty straightforward in Go, similar to most other languages:
// maths.go
// Calculate val to the n'th power
func Pow(val, n int) int {
for i:= 1; i < n; i++ {
val *= val
}
return val
}
// main.go
func main() {
four_squared := maths.Pow(4, 2)
fmt.Printf("4^2 = %d\n", four_squared)
}
Cool, this worked. I have successfully reinvented a small wheel1.
Do-While
The other trusty workhorse! Most languages have some form of this construct that says something like:
while statement is true:
do something
But not Go, apparently! Or at least, not explicitly. In for-loops, the first and last arguments - defining a variable and performing an operation on it - are totally optional, so a while loop is just a for-loop2:
// maths.go
func Mod(a, b int) int {
remainder := a
for remainder >= b {
remainder -= b
}
return remainder
}
If-else-then
The third trusty workhorseman of the Gopocalypse3. Basic if-statements are pretty straightforward:
// maths.go
func Divide(a, b int) int {
if a == 0 {
return 0
}
if b == 0 {
return 0
}
return a / b
}
Which could be cleaned up to use else-if:
// maths.go
func Divide(a, b int) int {
if a == 0 {
return 0
} else if b == 0 {
return 0
}
}
You can also add variable declarations to if-statements, which are then only accessible inside the blocks:
// maths.go
func Min(a, b int) int {
if v := a - b; v > 0 {
return b
} else {
return a
}
}
Okay, so that's covered most of the control structures off the top of my head. On my to-do list for the next couple of days are: working with arrays, and testing.