How to turn NaN from parseInt into 0 for an empty string?

Lean on the robustness of Number()

Number() converts strings to numbers sans dramatics and treats empty strings as 0:

const result = Number('');
console.log(result); // 0, happy days tomorrow
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Number() avoids the decimal-to-binary conundrums that parseInt thrusts upon us.

Bitwise OR: Punchy, Yet Opinionated

For syntax that's short and sweet but may confound the uninitiated, try bitwise OR:

const result = (parseInt('') | 0);
console.log(result); // 0, even for NaN, take that!
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A caveat: this method insists on an int. It's the TypeScript in a world of JavaScript.

Customize with a Helper Function

For reusable and consistent NaN handling, consider a bespoke helper function:

function parseToIntOrZero(str) {
    const parsed = parseInt(str);
    return isNaN(parsed) ? 0 : parsed;  // Be the change(NaN) you want to see in the world
}
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Handy in multiple zones of your app. Maximum impact, minimum effort!

Quirks of Implicit Conversion and Conditionals

Understanding the falsiness of 0 is crucial, especially when coding conditional checks:

const number = parseInt(s) || 0;      // Redirects 0 to a wrong turn
const safeNumber = Number(s) || 0;    // Okay Google, take me home
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Rely on the Number() constructor or bitwise OR to treat 0 as a true value.

Fathom the 'why' of Parsing

Ask yourself:

• Do I covet integer precision?
• Must spaces within strings become passe?
• What's my stance on input validation?

Choose the method that best fits into your project's requirements.