How Do I Access JavaScript Object Properties with Hyphens?

Understanding Property Access in JavaScript Objects with Hyphens

In web development, accessing object properties is crucial. However, properties with hyphens, such as CSS style properties, present challenges. To address this issue, it's essential to understand the limitations of dot notation and utilize alternative methods.

Limitations of Dot Notation

As you encountered, accessing properties with hyphens using dot notation (e.g., style.text-align) results in errors because the hyphen is interpreted as a minus sign. To overcome this, the key notation must be employed.

Key Notation

Key notation involves using square brackets ([]) to access object properties. For properties with hyphens, the following syntax is required:

obj["key-with-hyphen"]

Applying this to your code, you can retrieve the "text-align" property as follows:

style["text-align"]

Additional Considerations

When accessing properties using key notation, keep the following in mind:

• Use String Literals: Property keys with hyphens must be enclosed in string literals since they are evaluated dynamically.
• Arrays as Objects: Arrays in JavaScript are objects, and object properties can be accessed using the same syntax.
• Regex for Valid Property Names: The following regular expression ensures that property names conform to JavaScript naming conventions:

[a-zA-Z_$][0-9a-zA-Z_$]*

By incorporating these concepts, you can efficiently access JavaScript object properties with hyphens, enabling you to manipulate CSS styles and other objects with ease.

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