Return values in Blockchain / Solidity - Step-by-Step Execution

Concept Flow - Return values

Function called

↓

Execute function code

↓

Return value encountered

↓

Send value back to caller

↓

Caller receives value

↓

Use returned value

When a function runs, it does its work and then sends a value back to where it was called from.

Execution Sample

Blockchain / Solidity

function getBalance() {
  return 100;
}

let balance = getBalance();
console.log(balance);

This code defines a function that returns 100, then stores and prints that value.

Execution Table

Step	Action	Evaluation	Result
1	Call getBalance()	Function starts	Execution enters getBalance
2	Execute return 100	Return value 100	Function ends, returns 100
3	Assign returned value	balance = 100	Variable balance now 100
4	Print balance	console.log(100)	Output: 100
5	End	No more code	Program stops

💡 Function returns value 100, which is assigned and printed; program ends.

Variable Tracker

Variable	Start	After getBalance call	Final
balance	undefined	100	100

Key Moments - 2 Insights

Why does the function stop running after return?

Because return sends the value back and immediately ends the function, as shown in step 2 of the execution_table.

What happens to the returned value?

It goes back to the caller and can be stored or used, like balance = 100 in step 3.

Visual Quiz - 3 Questions

Look at the execution_table, what is the value returned by getBalance() at step 2?

A undefined

B 100

C balance

D null

💡 Hint

Check the 'Evaluation' and 'Result' columns at step 2 in the execution_table.

At which step does the variable balance get its value?

A Step 1

B Step 2

C Step 3

D Step 4

💡 Hint

Look at the 'Action' column for when balance is assigned in the execution_table.

If the return statement was removed, what would happen to balance?

A balance would be undefined

B balance would be 100

C balance would be null

D balance would be NaN

💡 Hint

Without return, the function returns undefined by default; see variable_tracker for initial balance.

Concept Snapshot

Return values let a function send data back to where it was called.
Use 'return value;' inside the function.
After return, function stops running.
Caller can save or use the returned value.
Without return, functions return undefined by default.

Full Transcript

This visual trace shows how return values work in blockchain programming. When the function getBalance is called, it runs and hits the return statement which sends back the value 100. The function then stops running immediately. The caller receives this value and stores it in the variable balance. Finally, balance is printed to the console showing 100. Key points are that return ends the function and sends a value back, and the caller can use that value. If return is missing, the function returns undefined. This helps beginners see step-by-step how return values flow in code.