1---
2title: Early Return from Functions
3impact: LOW-MEDIUM
4impactDescription: avoids unnecessary computation
5tags: javascript, functions, optimization, early-return
6---
7 
8## Early Return from Functions
9 
10Return early when result is determined to skip unnecessary processing.
11 
12**Incorrect (processes all items even after finding answer):**
13 
14```typescript
15function validateUsers(users: User[]) {
16  let hasError = false
17  let errorMessage = ''
18  
19  for (const user of users) {
20    if (!user.email) {
21      hasError = true
22      errorMessage = 'Email required'
23    }
24    if (!user.name) {
25      hasError = true
26      errorMessage = 'Name required'
27    }
28    // Continues checking all users even after error found
29  }
30  
31  return hasError ? { valid: false, error: errorMessage } : { valid: true }
32}
33```
34 
35**Correct (returns immediately on first error):**
36 
37```typescript
38function validateUsers(users: User[]) {
39  for (const user of users) {
40    if (!user.email) {
41      return { valid: false, error: 'Email required' }
42    }
43    if (!user.name) {
44      return { valid: false, error: 'Name required' }
45    }
46  }
47 
48  return { valid: true }
49}
50```
51