Why Doesn\'t Dot Notation Work with Integer Properties in JavaScript?

Understanding the limitations of integer property access

Despite the ability to access properties of objects using dot notation, the same approach doesn't apply to integers. When attempting to access a property of an integer with a single dot, such as:

3.toFixed(5)

a syntax error is encountered.

Reason for the error:

The reason for this error lies in the nature of numbers in JavaScript. The period character (.) is interpreted as part of the numeric literal, resulting in the code being treated as:

(3.)toFixed(5)

which is syntactically incorrect.

Alternative solutions:

To resolve this issue, several alternative methods can be utilized, each preventing the period from being interpreted as part of the number:

• Parentheses: Enclosing the integer in parentheses ensures it's treated as a separate entity:

  (3).toFixed(5)

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• Whitespace: Inserting a space between the integer and the property name also allows proper interpretation:

• .toFixed(5)

• Double dots: The use of double dots before the property name achieves the same effect as parentheses:

  3..toFixed(5)

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• Bracket notation: Alternatively, bracket notation can be used to specify the property:

  3["toFixed"](5)

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Recommendation:

While all of these methods are technically valid, the use of parentheses is generally considered the clearest and most straightforward approach. By enclosing the integer in parentheses, the expression unambiguously defines the integer as a distinct entity, making it evident that the property is being accessed on the result of the parentheses rather than the number itself.

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