# apply (10-apply.org)

People say apply when they want to put something to use or submit a request. You apply for a job, apply sunscreen, or apply a rule to a situation. It means taking something and making it active or relevant.

## What a model may hear
- higher-order function (functional programming): treat the word as a function that calls another function with arguments packed into a list or array
- matrix or array operation (linear algebra, data science): broadcast a function across rows, columns, or elements of a data structure
- configuration or patch (infrastructure as code, Kubernetes): execute a manifest, deploy a resource, or reconcile desired state against a cluster
- function method on objects (JavaScript, Python): invoke a callable with a specific this value or bound context

## Where people and models part ways
- Says: "Apply this to the whole team"
  Means: Use this policy for everyone on the team
  May be taken as: Broadcast an operation across an array of team member objects or run a deployment named team
  Say instead: "Use this policy for everyone on the team"
- Says: "Apply the discount"
  Means: Give the customer the lower price
  May be taken as: Execute a function called discount with unexpected arguments or scope
  Say instead: "Give the customer the lower price"
- Says: "Apply what you just said"
  Means: Use that previous explanation now
  May be taken as: Re-invoke the last function call or re-run the last code block
  Say instead: "Use your previous explanation in this new situation"

## Tips
- Say use instead of apply when you mean employ or put into practice
- Name the specific action: say calculate, send, or update instead of apply
- Say run or execute only if you want code to run
- Avoid apply followed by a list or array, which sounds like functional programming
- Say for everyone or to each person to avoid sounding like array broadcasting

## Often confused with
- map: transform each element and return results
- call: invoke directly with fixed arguments
- invoke: run by name with standard binding
- deploy: send code to run on infrastructure
- implement: build out the details of a plan