Let vs Var

In Swift, you use let and var to store values.

var creates a variable — its value can be changed later:

var score = 10
print(score)  // 10
score = 20
print(score)  // 20

let creates a constant — its value cannot be changed once set:

let name = "Alice"
print(name)  // Alice
// name = "Bob"  // Error! Cannot assign to 'let' constant

When to use which?

• Use let by default. If a value doesn't need to change, make it a constant.
• Use var only when you know the value will need to change.

This is a best practice in Swift that makes your code safer and easier to understand.