Converting decimal to binary or hex based on a condition in JavaScript

Problem

We need to write a JavaScript function that takes in a number n and converts it based on a condition:

• If a number is even, convert it to binary.
• If a number is odd, convert it to hex.

Solution

We can use JavaScript's toString() method with different radix values to perform the conversion. For binary conversion, we use radix 2, and for hexadecimal conversion, we use radix 16.

Example

Here's the implementation:

const num = 1457;

const conditionalConvert = (num = 1) => {
   const isEven = num % 2 === 0;
   const toBinary = () => num.toString(2);
   const toHexadecimal = () => num.toString(16);
   
   return isEven 
      ? toBinary() 
      : toHexadecimal();
};

console.log(conditionalConvert(num));

5b1

How It Works

The function works by:

• Checking even/odd: Using the modulo operator num % 2 === 0
• Binary conversion: num.toString(2) converts to base-2
• Hex conversion: num.toString(16) converts to base-16
• Conditional return: Using ternary operator for clean logic

Testing Different Values

// Test with even numbers (should return binary)
console.log("Even number 8:", conditionalConvert(8));
console.log("Even number 16:", conditionalConvert(16));

// Test with odd numbers (should return hex)
console.log("Odd number 15:", conditionalConvert(15));
console.log("Odd number 255:", conditionalConvert(255));

Even number 8: 1000
Even number 16: 10000
Odd number 15: f
Odd number 255: ff

Simplified Version

Here's a more concise version of the same function:

const simpleConvert = (num) => {
   return num % 2 === 0 ? num.toString(2) : num.toString(16);
};

console.log("Simple version - 1457:", simpleConvert(1457));
console.log("Simple version - 20:", simpleConvert(20));

Simple version - 1457: 5b1
Simple version - 20: 10100

Conclusion

Using JavaScript's toString() method with different radix values provides an elegant solution for conditional number base conversion. The modulo operator effectively determines whether to convert to binary or hexadecimal format.