String Manipulation String Conversion Bit Manipulation
Learner Level

Implement the binaryStringToDecimal method that converts a binary string into its decimal integer value.

The input contains a string binary made of binary digits 0 and 1. Your task is to convert this binary number into its decimal integer value.

Each digit contributes based on its position from right to left. For example, 101 means 1×4 + 0×2 + 1×1, so the answer is 5.

Example 1
Input:
binary (string) = 101
Return:
(int) 5
Example 2
Input:
binary (string) = 1111
Return:
(int) 15
Example 3
Input:
binary (string) = 0
Return:
(int) 0

Read the binary string from left to right and build the decimal value step by step.

Whenever a new binary digit is read, multiply the current decimal value by 2 and add the current digit. This works because moving one position in binary is the same as shifting the value left by one bit.

Pseudocode:

function binaryStringToDecimal(binary):
    decimal = 0
    for each character ch in binary:
        digit = numeric value of ch
        decimal = decimal * 2 + digit
    return decimal
Run your code to see the result.