How to Check if a Map is Empty in Go - Step by Step Examples

How to Check if a Map is Empty in Go ?

Answer

To check if a map is empty in Go, you can check the length of the map using the len function. If the length is zero, the map is empty.


✐ Examples

1 Checking if a Map is Empty Using len Function

We can check if a map is empty in Go by using the len function, which returns the number of elements in the map. If the length is zero, the map is empty.

For example,

  1. We start by declaring and initializing an empty map named myMap. In this example, the map has string keys and integer values.
  2. We use the len function to check if the map is empty. The len function returns the number of elements in the map.
  3. If the length is zero, we print a message indicating that the map is empty. Otherwise, we print a message indicating that the map is not empty.

Go Program

package main

import "fmt"

func main() {
    // Declare and initialize an empty map
    myMap := map[string]int{}

    // Check if the map is empty using len function
    if len(myMap) == 0 {
        fmt.Println("Is the map empty? Yes")
    } else {
        fmt.Println("Is the map empty? No")
    }
}

Output

Is the map empty? Yes

2 Checking if a Non-Empty Map is Empty Using len Function

We can check if a non-empty map is empty in Go by using the len function, which returns the number of elements in the map. If the length is greater than zero, the map is not empty.

For example,

  1. We start by declaring and initializing a map named myMap with some key-value pairs. In this example, the map has string keys and integer values.
  2. We use the len function to check if the map is empty. The len function returns the number of elements in the map.
  3. If the length is zero, we print a message indicating that the map is empty. Otherwise, we print a message indicating that the map is not empty.

Go Program

package main

import "fmt"

func main() {
    // Declare and initialize a map
    myMap := map[string]int{
        "one": 1,
        "two": 2,
        "three": 3,
    }

    // Check if the map is empty using len function
    if len(myMap) == 0 {
        fmt.Println("Is the map empty? Yes")
    } else {
        fmt.Println("Is the map empty? No")
    }
}

Output

Is the map empty? No

3 Checking if a Map is Empty After Clearing Using len Function

We can check if a map is empty in Go after clearing its elements using the len function, which returns the number of elements in the map. If the length is zero, the map is empty.

For example,

  1. We start by declaring and initializing a map named myMap with some key-value pairs. In this example, the map has string keys and integer values.
  2. We use a loop to clear the map by deleting all its elements using the delete function.
  3. We use the len function to check if the map is empty. The len function returns the number of elements in the map.
  4. If the length is zero, we print a message indicating that the map is empty. Otherwise, we print a message indicating that the map is not empty.

Go Program

package main

import "fmt"

func main() {
    // Declare and initialize a map
    myMap := map[string]int{
        "one": 1,
        "two": 2,
        "three": 3,
    }

    // Clear the map
    for k := range myMap {
        delete(myMap, k)
    }

    // Check if the map is empty using len function
    if len(myMap) == 0 {
        fmt.Println("Is the map empty? Yes")
    } else {
        fmt.Println("Is the map empty? No")
    }
}

Output

Is the map empty? Yes

Summary

In this tutorial, we learned How to Check if a Map is Empty in Go language with well detailed examples.


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  5. How to Set a Default Value for a Key in a Map in Go ?
  6. How to Update the Value for a Key in a Map in Go ?
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  8. How to Check if a Key Exists in a Map in Go ?
  9. How to Check if a Value Exists in a Map in Go ?
  10. How to Get the Value Associated with a Key in a Map in Go ?
  11. How to Remove a Key-Value Pair from a Map in Go ?
  12. How to Remove Key-Value Pairs from a Map Based on Values in Go ?
  13. How to Clear All Key-Value Pairs from a Map in Go ?
  14. How to Iterate Over Keys in a Map in Go ?
  15. How to Iterate Over Values in a Map in Go ?
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  17. How to Get the Size (Number of Key-Value Pairs) of a Map in Go ?
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  20. How to Convert a Map to an Array of Key-Value Pairs in Go ?
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  24. How to Sort a Map by Keys in Go ?
  25. How to Sort a Map by Values in Go ?
  26. How to Filter a Map Based on Keys in Go ?
  27. How to Filter a Map Based on Values in Go ?
  28. How to Reduce Values in a Map to a Single Value in Go ?
  29. How to Convert an Array of Key-Value Pairs to a Map in Go ?
  30. How to Convert a Map to a JSON String in Go ?
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