tact-cookbook.md

Tact Cookbook

The core reason for creating the Tact Cookbook is to collect all the experience from Tact developers in one place so that future developers will use it!

Compared to the FunC Documentation, this article is more focused on everyday tasks every FunC developer resolve during the development of smart contracts.

Basics

How to write a Hello World smart contract

contract HelloWorld {

    get fun greeting(): String {
        return "hello world";
    }

}

How to write an 'if' statement in Tact

Tact supports if statements in a similar syntax to most programming languages. The condition of the statement can be any boolean expression.

value: Int = 9001;

if (value > 10) {
    // do something
}

if (value > 100) {
    // do something
} else {
    // do something else
}

if (value > 9000) {
    // do something
} else if (value > 500) {
    // do another thing
} else {
    // do something else
}

Slice

How to determine if slice is empty

Slice is considered empty if it has no stored data and no stored references.

Use empty() method to check if a slice is empty.

// Create an empty slice with no data and no refs
let empty_slice: Slice = emptyCell().asSlice();
// Returns `true`, because `empty_slice` doesn't have any data or refs
empty_slice.empty();

// Create a slice with some data
let slice_with_data: Slice = beginCell().
    storeUint(42, 8).
    asSlice();
// Returns `false`, because the slice has some data
slice_with_data.empty();

// Create a slice with a reference to an empty cell
let slice_with_refs: Slice  = beginCell().
    storeRef(emptyCell()).
    asSlice();
// Returns `false`, because the slice has a reference
slice_with_refs.empty();

// Create a slice with data and a reference
let slice_with_data_and_refs: Slice  = beginCell().
    storeUint(42, 8).
    storeRef(emptyCell()).
    asSlice();
// Returns `false`, because the slice has both data and reference
slice_with_data_and_refs.empty(); 

💡 Useful links

• empty() in docs
• dataEmpty() in docs
• refsEmpty() in docs
• emptyCell() in docs