How Can I Ensure My JavaScript Variables Are Neither Null Nor Undefined?

Ensuring Non-Null and Non-Undefined Variable Values in JavaScript

Determining whether a variable has a defined value that is not null or undefined is common in JavaScript programming. While the provided function attempts to handle these cases, it may not cover all scenarios.

The recommended approach is to verify the variable's truthiness. If a variable has a truthy value, it signifies that it's not:

• Null
• Undefined
• NaN
• Empty string ("")
• 0
• False

This approach can be used as follows:

if (value) {
    // Perform actions...
}

Alternatively, if the variable's existence is uncertain, the typeof operator can be employed:

if (typeof foo !== 'undefined') {
    // foo may be resolved and defined
}

However, if it's known that the variable is declared, directly checking for a truthy value is preferred.

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