Asterisk: Definition and Uses

The asterisk (*) character is a versatile symbol used as a reference mark for footnotes, to represent multiplication, and as a 'wildcard' in searches.

The asterisk (*) is a symbol with various uses in different contexts, including notation in mathematics, computing, and written language.

Functions of Asterisk

Mathematical Notation

The asterisk is commonly used to represent the multiplication of numbers or variables:

$$ a * b = c $$

For example, in many programming languages, the expression 5 * 3 results in 15.

Footnotes and References

In written texts, the asterisk is often used to indicate a footnote or an annotation. For example:

“Mathematics is a subject that requires practice.*”

* This statement can be backed by numerous studies indicating the importance of practice in learning mathematics.

Wildcard Searches

In computing, the asterisk acts as a “wildcard” character, representing zero or more characters in searches or filenames. It allows for flexible searching and file management:

• *.txt searches for all text files.
• file* finds files starting with “file.”

Special Considerations

Context Sensitivity

While the asterisk serves multiple functions, its meaning is context-dependent. Proper usage ensures clarity, especially in documents mixing mathematical, textual, and computing elements.

Escaping in Computing

In certain programming languages and computing environments, an asterisk might need to be ’escaped’ using a backslash (*) to be interpreted literally rather than as a wildcard.

Examples

Mathematics

1In mathematics, an asterisk often denotes multiplication:
2
  

  $$ 7 * 8 = 56 $$

Footnotes

1When reading scholarly articles, you might notice:
2"The results are statistically significant.*"
3\* Detailed results are available in the supplementary materials.

Wildcard Searches

1To list all files with the `.jpg` extension in a directory:
2$ ls *.jpg

Historical Context

The asterisk has been used for centuries, appearing in various ancient manuscripts to indicate footnotes or annotations. Its application in computing as a wildcard character emerged during the early days of programming and file management.

Related Terms

• Footnote: A note at the bottom of the page providing additional information.
• Multiplication: A mathematical operation where two numbers (multiplicands) are combined to produce a product.
• Wildcard Character: A symbol used to replace or represent one or more characters.

FAQs

Q1: Can an asterisk be used in file names?

A1: Generally, asterisks are not allowed in file names because they are reserved for wildcard operations. Always check your operating system’s guidelines.

Q2: How do I escape an asterisk in a string?

A2: You can escape an asterisk in many programming languages using a backslash (\*).

Q3: Are multiple asterisks used for multiple footnotes?

A3: Yes, typically, subsequent footnotes on the same page might use double asterisks (), triple asterisks (*), etc.

Summary

The asterisk (*) is a multi-functional symbol used across various disciplines. Its applications range from representing multiplication in mathematics, indicating footnotes in textual documents, to acting as a wildcard character in computing. Understanding its context-dependent usage enhances clarity and precision in communication.

References

1. “The Unicode Standard, Version 13.0”, Unicode Consortium.
2. “Mathematical Notation: A Guide for Engineers and Scientists”, by Harold J. Raveche.
3. “Computer System Administration”, by Edward Bailey.

Use this comprehensive entry as a quick guide to understanding the asterisk and its versatile applications!