Length of the string without using len() function in Python

Understanding String Length Calculation

The length of a string is the number of characters it contains. In Python, we can determine this without using the built-in len() function.

We will explore three different methods to find the length of a string in Python.

Method 1: Using a Loop

This method uses a loop to count the characters in the string.

def string_length_loop(string):
    length = 0
    for _ in string:
        length += 1
    return length

string = input("Enter a string: ")
print("Length of the string is", string_length_loop(string))
            

Method 2: Using Recursion

This method calculates the length of the string recursively.

def string_length_recursive(string, index=0):
    if string == "":
        return index
    return string_length_recursive(string[1:], index + 1)

string = input("Enter a string: ")
print("Length of the string is", string_length_recursive(string))
            

Method 3: Using Character Array

This method converts the string to a character list and counts its elements.

def string_length_array(string):
    char_list = list(string)
    length = 0
    for _ in char_list:
        length += 1
    return length

string = input("Enter a string: ")
print("Length of the string is", string_length_array(string))