Go – For Loop Range Int

Go – For Loop Range Int

The range keyword simplifies iteration by providing both the index and the value of each element.

In this tutorial, we will demonstrate how to use the For Loop with the range keyword to iterate over slices of integers with practical examples and provide detailed explanations.

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Iterating Over Slices of Integers

The range keyword is used to loop through slices and provides two values for each iteration: the index and the corresponding value. Below are examples of iterating through slices of integers.

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Example 1: Iterating Over Integers with Index and Value

Here’s an example of iterating through a slice of integers and printing both the index and value:

package main

import "fmt"

func main() {
    // Declare a slice of integers
    numbers := []int{10, 20, 30, 40, 50}

    // Iterate over the slice using range
    for index, value := range numbers {
        fmt.Printf("Index: %d, Value: %d\n", index, value)
    }
}

Explanation

1. Declare a Slice: A slice named numbers is initialized with integer values.
2. Use Range: The range keyword is used to iterate over the slice, providing the index and value for each element.
3. Print Index and Value: The index and value are printed using fmt.Printf.

Output

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Example 2: Ignoring the Index

If you only need the values, you can ignore the index by using the underscore (_):

package main

import "fmt"

func main() {
    // Declare a slice of integers
    numbers := []int{10, 20, 30, 40, 50}

    // Iterate over the slice, ignoring the index
    for _, value := range numbers {
        fmt.Println("Value:", value)
    }
}

Explanation

1. Declare a Slice: A slice named numbers is initialized with integer values.
2. Use Range: The range keyword is used to iterate over the slice.
3. Ignore the Index: The index is ignored by replacing it with an underscore (_), and only the values are printed.

Output

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Example 3: Ignoring the Value

If you only need the indices, you can ignore the values:

package main

import "fmt"

func main() {
    // Declare a slice of integers
    numbers := []int{10, 20, 30, 40, 50}

    // Iterate over the slice, ignoring the values
    for index := range numbers {
        fmt.Println("Index:", index)
    }
}

Explanation

1. Declare a Slice: A slice named numbers is initialized with integer values.
2. Use Range: The range keyword is used to iterate over the slice.
3. Ignore the Value: The values are ignored by replacing them with an underscore (_), and only the indices are printed.

Output

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When to Use Range for Integers

You can use range for integer with for loop:

• When you need to process or transform each integer in a slice.
• When you need both the index and the value of elements in a slice.
• When you need to count elements or calculate statistics on integer data.

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Conclusion

The for loop with range is a powerful tool for iterating over slices of integers in Go. By using or ignoring the index or value as needed, you can efficiently process data in your programs.