Oliver's Blog
Search
K
Comment on page

Decision Making

STATEMENT
DESCRIPTION
if Statements
Block of statement executed only when specified test expression is true.
if else Statements
When we want to execute some block of code if a condition is true and another block of code if a condition is false, In such a case we use if….else statement.
nested If Statements
When there is an if statement inside another if statement then it is known as nested if else.
switch Statement
A switch statement evaluates an expression against multiple cases in order to identify the block of code to be executed.
Above statements are standard as in many other languages, such as C and Java.

If with short statement

In Go, the conditional expression can be preceded by a simple statement, which is executes before the conditional expression is evaluated, and if it is a declaration statement then the variable declared in the statement will only be available inside the if block and it’s else or else-if sections.
package main
import "fmt"
func main() {
if x := 3; x%2 == 0 {
fmt.Printf("%d is even\n", x)
} else {
fmt.Printf("%d is odd\n", x)
}
}
3 is odd

Switch Statement (single cases)

package main
import "fmt"
func main() {
var dayOfWeek = 5
switch dayOfWeek {
case 1:
fmt.Println("Today is Monday.")
case 2:
fmt.Println("Today is Tuesday.")
case 3:
fmt.Println("Today is Wednesday.")
case 4:
fmt.Println("Today is Thursday.")
case 5:
fmt.Println("Today is Friday.")
case 6:
fmt.Println("Today is Saturday.")
case 7:
fmt.Println("Today is Sunday.")
default:
fmt.Println("Invalid weekday!")
}
}
Today is Friday.

Switch Statement (multiple cases)

package main
import "fmt"
func main() {
var dayOfWeek = 3
switch dayOfWeek {
case 1, 2, 3, 4, 5:
fmt.Println("It's a weekday.")
case 6, 7:
fmt.Println("It's the weekend!")
default:
fmt.Println("Invalid day!")
}
}
It's a weekday.

Switch Statement - fallthrough

All the following cases are executed after a match is found in the switch statement cases.
package main
import "fmt"
func main() {
var x = 2
switch x {
case 1:
fmt.Println("1")
fallthrough
case 2:
fmt.Println("2")
fallthrough
case 3:
fmt.Println("3")
}
}
2
3

Switch Statement - Short Statement

Similar to short statement for if statement.
package main
import "fmt"
func main() {
switch dayOfWeek := 5; dayOfWeek {
case 1, 2, 3, 4, 5:
fmt.Println("It's a weekday.")
case 6, 7:
fmt.Println("It's the weekend!")
default:
fmt.Println("Invalid day!")
}
}
It's a weekday.

Switch Statement - No Expression

package main
import "fmt"
func main() {
var marks = 40
switch { // same as `switch true`
case marks > 60:
fmt.Println("You got A!")
case marks < 60 && marks >= 50:
fmt.Println("You got B.")
case marks < 50 && marks >= 35:
fmt.Println("You got C :(")
default:
fmt.Println("Failed!")
}
}
You got C :(
Last modified 2yr ago