﻿ How to get Square of all array values in Python

# How to get Square of all array values in Python

Let us assume, I have an array of values (numbers) and I want to get the square of each array value, without running a loop like "for" etc. I can do this using recursion in Python.

A recursion refers to a function calling itself repeatedly till it meets a certain condition. It has to stop at one point.

So we are going use recursion in Python to get the Square of each value in an array.

## Get Square of a number in Python

But first, let us see how to get the square of a number in Python.

```def square(number):
return number * number

result = square(4)
print (result)	 # Output: 16```

If its a single number, we can simply multiply the number to itself to get the square.

## Using Recursion in Python

If there's an array of numbers, we can use recursion to get the square of all the values. For example,

```def square(number):
return [number[0]**2] + square(number[1:]) if number else []

arr = [2,4,6]
result = square(arr)
print (result)	# Output: [4, 16, 36]```

I am using power operator in the above example, to get the square of a value. ** is the called the power operator.

So, if you want get the square of 8 using the "power operator" (**), you can do something like this

```def square():
return [8 ** 2]

result = square()
print (result)```

➡️ In-addition, you can use Python's built-in pow() function to get the square of all numbers in an array without using loop. See the next article.