Early Return from Functions
Install this skill
npx skills add vercel-labs/agent-skillsWorks across Claude Code, Cursor, Codex, Copilot & Antigravity
The early return pattern improves code execution by exiting a function as soon as a definitive result is identified. By eliminating unnecessary code paths and state tracking, this approach minimizes overhead and prevents redundant operations. In complex loops or validation chains, avoiding the processing of remaining items once a target condition is met reduces CPU cycles and simplifies logic. This coding style enforces flatter structures, reducing deep nesting of if-else statements that often make scripts harder to read. Instead of maintaining boolean flags or accumulation variables, the function terminates with the final value immediately. This practice results in cleaner, more maintainable scripts that fail fast and remain highly efficient under heavy data loads or complex conditional branching logic common in agent-based processing.
When to Use This Skill
- •Validating incoming user input for missing fields
- •Searching through large arrays for a single specific record
- •Implementing authentication checks before executing core business logic
- •Processing API responses where a failure status requires immediate abandonment
How to Invoke This Skill
Example prompts that trigger this skill in Claude Code, Cursor, or Antigravity:
- “Refactor this function to use early returns
- “Stop processing this loop once a match is found
- “Clean up this nested if logic for better performance
- “Remove boolean flags and use early returns instead
- “Optimize this validator to exit on the first error
What this skill does
- •Terminates execution loops immediately upon error discovery
- •Eliminates the need for tracking boolean state flags
- •Reduces function cyclomatic complexity by flattening logic
- •Prevents unnecessary computation on remaining data sets
- •Simplifies control flow by isolating edge cases at the top of a function
When not to use it
- ✕When cleanup logic like database connection closing must execute regardless of the result
- ✕When you need to collect all errors from a list rather than just the first one found
Example workflow
- Analyze the function for deeply nested logic or persistent state variables
- Identify the primary success condition and negative edge cases
- Move negative edge cases to the top of the function
- Replace conditional assignment with immediate return statements
- Remove redundant variables that previously tracked loop status
- Test the function to ensure final return remains reachable
Pitfalls & limitations
- !Accidentally bypassing necessary cleanup code like resource disposal
- !Returning partial results when an aggregated collection was expected
- !Making the logic harder to follow if over-applied to simple functions
FAQ
How it compares
While manual coding often uses flag variables that require tracking state throughout an entire block, early return simplifies the logic by terminating immediately upon reaching the desired outcome.
📄 Full skill instructions — original source: vercel-labs/agent-skills
Return early when result is determined to skip unnecessary processing.
**Incorrect (processes all items even after finding answer):**
function validateUsers(users: User[]) {
let hasError = false
let errorMessage = ''
for (const user of users) {
if (!user.email) {
hasError = true
errorMessage = 'Email required'
}
if (!user.name) {
hasError = true
errorMessage = 'Name required'
}
// Continues checking all users even after error found
}
return hasError ? { valid: false, error: errorMessage } : { valid: true }
}**Correct (returns immediately on first error):**
function validateUsers(users: User[]) {
for (const user of users) {
if (!user.email) {
return { valid: false, error: 'Email required' }
}
if (!user.name) {
return { valid: false, error: 'Name required' }
}
}
return { valid: true }
}How to Use This Skill Unit
Option A: Project-Specific (Recommended)
- Click "Download" above
- In your project, create the directory:
.agent/skills/js-early-exit/ - Save the file as
SKILL.md - The agent will automatically discover the skill based on its description.
Option B: Global Installation (All Agents)
Save the file to these locations to make it available across all projects:
- Claude Code:
~/.claude/skills/vercel-labs/agent-skills/js-early-exit/SKILL.md - Cursor:
~/.cursor/skills/vercel-labs/agent-skills/js-early-exit/SKILL.md - Antigravity:
~/.gemini/antigravity/skills/vercel-labs/agent-skills/js-early-exit/SKILL.md
🚀 Install with CLI:npx skills add vercel-labs/agent-skills
