Testing whether a value is odd or even
Checking if a number is even or odd can be simply done with the modulus operator %
. For even numbers, the operation number % 2
equals 0
. Here's the core code:
Input validation and exception handling
In a practical coding scenario, you will need to validate the input first. This guard check will ensure the input is a finite number:
Notice negative numbers are implicitly handled. However, using absolute values can make this more obvious:
Tackling string inputs
Not all numbers come nicely packed as numbers. Sometimes they sneak in as strings ๐ต๏ธโโ๏ธ. Trim the whitespaces and transform the strings into numbers to uphold justice:
Enhancing performance
In performance-critical applications, using the bitwise AND operator &
provides a super speedy even check:
Remember, JavaScript bitwise operations work on 32-bit integers. Very large numbers or non-integer values may introduce mind-bendy results.
Regular expressions to the rescue
When squaring off against strings representing numbers, regular expressions (regex) are your mighty sword and shield:
This regex cut handles negative and positive integers like a seasoned samurai.
Special number cases
Infinity keeps claiming it's a number, but it doesn't act like one. It's a special case, as are other type coercion quirks. A fighter must be prepared:
For robustness, handle such cases effectively:
Cross-browser compatibility
Every browser has its quirks, and respects JavaScript in its own unique way. To ensure that your function plays nice with everyone, test across different browsers. Unexpected issues can pop up, especially when using the latest ECMAScript magic.
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