placeholder

Thân thiện

A student uses a placeholder in a simple algebra equation.

Definition

1. Noun:
   • A symbol in an expression: A symbol (like 'x' or '□') used in a logical or mathematical statement to represent an unspecified element from a defined set. Its value can be assigned or substituted later.
   • A temporary or interim substitute: Something used or someone who acts to occupy a position, role, or space temporarily until the final or permanent person or thing is available.

Usage Examples

• Noun (Symbol):
  • In the equation 2x + 3 = 7, the letter x is a placeholder for the unknown number.
  • The form used a _____ as a placeholder where the user should write their name.
• Noun (Temporary Substitute):
  • We used a generic image as a placeholder on the website until the final photos were ready.
  • She served as a placeholder on the committee until a permanent chair could be elected.

Advanced Usage

• In computing/programming: A variable, piece of text, or graphic used in software development or web design to stand in for data that will be inserted later.
  • The developer used {username} as a placeholder in the code, which the system replaces with the actual user's name.
• In formal contexts: Can describe a person holding a position with little real power, often awaiting a successor.
  • The interim manager was merely a placeholder, maintaining operations until the new CEO started.

Variants and Related Words

• Proxy (n): A person authorized to act on behalf of another. (Closer to the "person authorized" sense).
• Dummy (n): A model or substitute used for display or testing.
• Stub (n): In computing, a minimal, temporary implementation of a software component.

Synonyms

• Symbolic representation: Variable, symbol, blank.
• Temporary substitute: Stand-in, fill-in, stopgap, interim.

Related Phrases

• Placeholder name: A generic name (like "John Doe" or "Acme Corporation") used when the specific name is unknown or unimportant.
  • For the example, use a placeholder name like "Company XYZ".
• Placeholder text: Generic, nonsensical text (like "lorem ipsum") used to demonstrate a document's visual form.
  • The graphic designer filled the brochure layout with placeholder text.

Notes on Meaning

The two core meanings are connected by the concept of temporary substitution. The first is abstract and symbolic (mathematics, logic), while the second is concrete and practical (roles, objects, text). In modern usage, especially in technology and media, the "temporary substitute" meaning is predominant.

Học thuật

Noun

1. a symbol in a logical or mathematical expression that can be replaced by the name of any member of specified set
2. a person authorized to act for another

Từ đồng nghĩa

• proxy
• procurator