# Golang length of map [2 Easy Methods]

Topics we will cover

In this tutorial we will explore different methods we can use to get length of map in golang.

## Different methods to get golang length of map

### Method-1: Use the len() function

AÂ map is an unordered collection of key-value pairs, where each key is unique. In Go programming, use the `len()` function and pass the `map` as an argument to get the length of a map.

In this example, we will learn how to use the `len()` function to get the length of a given map:

Syntax: The syntax to find the length of MapÂ `x` is:

`len(x)`
The function returns an integer indicating how many key-value pairs are in the map.Â In the following example, we'll count the items in the map `studentRecord`, where the student name is a key and the score is a value.

``````package main

import (
"fmt"
)

func main() {

//initialize a map
scoreRecord := map[string]float64{
"Ariana": 8.6,
"Bob":    9.3,
"Clover": 7.8,
"Daniel": 9,
}

//calculate the length of the map
mapLength := len(scoreRecord)

//display the length
fmt.Println("Map is:", scoreRecord)
fmt.Println("Length of map :", mapLength)
}
``````

Output:

```Map is: map[Ariana:8.6 Bob:9.3 Clover:7.8 Daniel:9]
Length of map : 4```

Explanation

• Firstly, declare and initialize the map, where the key is of data type string and value is of data type int.
• Calculate the length of the map using the`len()` length and pass the map as a parameter to it, then assign the returned length to `mapLength`.
• Print out the map and the length `mapLength` of the map.

### Method-2: Iterate over the map to count all elements in a nested map

We can use `range` statement to iterate over the map and count the number of elements in a nested map.

``````package main

import "fmt"

func main() {

//initialize a nested map
scoreRecord := map[string][]float64{
"Ariana": []float64{5.3, 7.3, 6.9},
"Bob":    []float64{8.3, 8.7, 9.2},
"Clover": []float64{7.6, 9.2},
"Daniel": []float64{8.8, 9.0, 8.9},
}

//initialize a counter
counter := 0
for _, v := range scoreRecord {
// add up the number of elements in nested map
counter += len(v)
}

fmt.Println("Number of elements in nested map is:", counter)
}``````

Output:

`Number of elements in nested map is: 11`

## Summary

In this Golang Tutorial, we learned how to find the length of a Map, using two different methods:

• Using `len()` function
• Iterate over the map to count the elements

## References

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Tuan Nguyen

He is proficient in Golang, Python, Java, MongoDB, Selenium, Spring Boot, Kubernetes, Scrapy, API development, Docker, Data Scraping, PrimeFaces, Linux, Data Structures, and Data Mining. With expertise spanning these technologies, he develops robust solutions and implements efficient data processing and management strategies across various projects and platforms. You can connect with him on LinkedIn.

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