Why View and pure functions in Blockchain / Solidity? - Purpose & Use Cases

The Big Idea

Discover how to check blockchain data instantly without spending a single coin or changing anything!

The Scenario

Imagine you want to check a bank account balance or calculate interest without changing anything in the account. Doing this manually means writing code that might accidentally change data or cost extra fees every time you check.

The Problem

Without special functions, reading data can be slow, costly, and risky because it might alter the blockchain state or use unnecessary resources. This makes simple checks complicated and expensive.

The Solution

View and pure functions let you safely read or compute data without changing anything on the blockchain. They run without cost and guarantee no side effects, making your code efficient and trustworthy.

Before vs After

✗ Before

function getBalance() public returns (uint) { return balance; }

✓ After

function getBalance() public view returns (uint) { return balance; }

What It Enables

It enables free, safe, and efficient data reading and calculations on the blockchain without risking unwanted changes or costs.

Real Life Example

Checking your cryptocurrency wallet balance or calculating token rewards instantly without paying gas or changing your account.

Key Takeaways

View and pure functions let you read or compute data without changing blockchain state.

They save cost and prevent accidental data changes.

They make blockchain apps faster and safer for users.