Conditional Statements

Conditional Statements, also known as if-else statements, are used to execute a block of code based on a condition.

Conditions are represented by boolean expressions, which we briefly explored in the second section's "Booleans" chapter. To recall, a boolean expression is a combination of logical and/or comparison operations and may or may not include other operators.

A conditional statement uses if, else if, and else keywords. The syntax for writing a simple conditional statement is as follows:

If the value of the 'expression' in the parentheses is true, the code enclosed in the curly brackets is executed. Otherwise, it is ignored. Here is an example:

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package main
import "fmt"

func main() {
      fmt.Println("Before if-condition")
      if (3 < 4) {
            fmt.Println("3 is greater than 4")
      }
      fmt.Println("After if-condition")
}

Since the expression 3 < 4 evaluates to true, the code inside the curly braces is executed. If we modify the expression to make it false, the Println statement won't be executed.

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package main
import "fmt"

func main() {
      fmt.Println("Before if-condition")
      if (3 > 4) {
            fmt.Println("3 is greater than 4")
      }
      fmt.Println("After if-condition")
}

The following diagram shows the execution of the if-condition:

You can use the else keyword to specify code that should be executed when the condition is not met. The else statement does not require a boolean expression.

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package main
import "fmt"

func main() {
    var value int = 70
    if (value <= 50) {
        fmt.Println("The value is less or equal to 50")
    } else {
        fmt.Println("The value is greater than 50")
    }
}

Here's how the execution flow unfolds when we use else in the condition:

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Section 3. Chapter 2