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# Python program to find the occurrence of a particular number in an array

Count occurrences of an element in an array: Here, we are going to learn how to find the occurrence of a particular number in an array using python program? By Suryaveer Singh Last updated : January 14, 2024

In this article, we would learn about **arrays** and how to code for an array question asked? So starting off we would first learn about arrays i.e. **what an array is?**

## ARRAY

An array can be defined as a container object that is used to hold a fixed number of values of a single type of data. The main purpose of an array is to store multiple items of the same type together.

Image source: https://cdncontribute.geeksforgeeks.org/wp-content/uploads/array-2.png

This is the simple idea that you need to understand about the array, now starting with the simple question.

## Problem statement

Suppose you are given with an array that contains ints. Your task is to return the number of 3 in the array.

## Example

Consider the below example with sample input and output:

count_occurrence([1, 2, 3], 3) = 1 count_occurrence([1, 3, 3], 3) = 2 count_occurrence([1, 3, 9, 3, 3], 3) = 3

## Solution approach

Here we have to again consider a variable which is initially equal to zero to keep the count of a number of 3 and also our function is only defined for nums as our array would only contain integers as mentioned earlier.

## Algorithm

The below are the algorithm steps to find the occurrence of a particular number in an array/list:

- Take a list of integers (an array) and a number whose occurrence is to be found.
- Create a function (count_occurrence()), pass list (numlist), and number (num).
- Define a counter variable (count) and initiate it with 0
- Inside the function, iterate the list.
- Compare each list element (value) with the given number (num) , if the list element is equal to the number, increase the value of the count.
- Return the count, that is the occurrences of the given number (num).

## Python program to find the occurrence of a particular number in an array

# Function that accepts a list and a number # and, returns the count of the given number def count_occurrence(numlist, num): count = 0 for value in numlist: if value == num: count = count + 1 return count # Main code # Call the function # Create a list list1 = [1, 2, 3, 4, 3, 3, 3] print("List is:", list1) # Find occurrence of 3 in list print("Occurrence of 3:", count_occurrence(list1, 3)) # Find occurrence of 1 in list print("Occurrence of 1:", count_occurrence(list1, 1)) # Find occurrence of 4 in list print("Occurrence of 4:", count_occurrence(list1, 4))

## Output

The output of the above program is:

List is: [1, 2, 3, 4, 3, 3, 3] Occurrence of 3: 4 Occurrence of 1: 1 Occurrence of 4: 1

To understand the above program, you should have the basic knowledge of the following Python topics:

- Python Variables
- Python Data Types
- Python print() Method
- Python Conditional Statements
- Python Loops
- Python Functions
- Python Functions Definitions and Calling

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