Once your provider, contract, and account are connected, you can interact with the contract :

# Interact with your contract :

- you can read the memory of the contract, without fees.
- you can write the memory, but you have to pay fees. On Mainnet, you have to pay fees with a bridged ETH token. On Testnet 1 & 2, you have to pay with a bridged Goerli ETH token. On devnet, you have to pay with a dummy ETH token. Your account shall be enough funded to pay fees (0.01 ETH should be enough to start).

![https://github.com/PhilippeR26/starknet.js/raw/guidesPRO/www/guides/pictures/Interact_contract.png](https://github.com/PhilippeR26/starknet.js/raw/guidesPRO/www/guides/pictures/Interact_contract.png)

Here we will interact with a test.cairo contract, already deployed in Testnet 1 and Tesnet 2, at addresses :

- testnet1 : [0x5f7cd1fd465baff2ba9d2d1501ad0a2eb5337d9a885be319366b5205a414fdd](https://testnet.starkscan.co/contract/0x5f7cd1fd465baff2ba9d2d1501ad0a2eb5337d9a885be319366b5205a414fdd#read-contract).
- testnet2 : [0x2367db6b0df07033d196dcd25961109d8fbc86227158343149742284c7582e](https://testnet-2.starkscan.co/contract/0x002367db6b0df07033d196dcd25961109d8fbc86227158343149742284c7582e#read-contract).We will use Testnet1, so you need a funded wallet in this network.

This contract contains a storage memory called `balance`.

- It can be read with the `@view function: get_balance()`
- Balance can be modified with the `@external function : increase_balance(amount1: felt, amount2: felt)`

`import { Provider, Contract, Account, ec, json } from "starknet";`

Newton

How can I interact with my contract on Starknet using starknetjs?

Is Kakarot a Starkware project? 

>Hello! This is day 5 of the 17 days of the Cairo Challenge. And I have no idea how to solve the [playground](https://www.cairo-lang.org/playground/) exercise “Revoked references”. Can you run these 6 steps and write down what you see?

```
// The scope of some types of references in Cairo (e.g., return values of
// functions and temporary variables) is somewhat restricted.
// For example, a call to another function may revoke those references.
//
// 1. Try to run the following code. You should get an error that `x` was revoked
//    (this is because of the second call to `foo`).
// 2. In simple cases, like this one, the compiler can solve this automatically
//    if the "alloc_locals" keyword is used within the function's scope.
//    Add "alloc_locals;" to the beginning of main(), and make sure the code works.
// 3. To understand what happens behind the scenes, replace "alloc_locals;" with
//    "ap += SIZEOF_LOCALS;" - this command allocates memory cells for local variables
//    (you'll need them below) but doesn't enable the mechanism that
//    automatically resolves revoked references.
//    Trying to run the code now should result in the original error.
// 4. Solve the problem manually by copying the value of `x` to a local variable
//    (e.g., "local x2 = x;"). Local variables are not revoked when functions
//    are called.
//    You can read more about local variables [here](https://www.cairo-lang.org/docs/how_cairo_works/consts.html#local-vars).
// 5. You can even use the same name: "local x = x;".
//    This is called "reference rebinding", where the meaning of `x` changes:
//      Before this line, `x` refers to the return value.
//      After that, `x` refers to the local variable.
// 6. A shorter syntax is "let (local x) = foo(10);" which achieves the same goal.
//    Try it!

%builtins output

from starkware.cairo.common.serialize import serialize_word

// Returns a^3 for a != 0 and 1 otherwise.
func foo(a) -> (res: felt) {
    if (a == 0) {
        return (res=1);
    } else {
        return (res=a * a * a);
    }
}

// Outputs the value 10^3 + 5^3.
func main{output_ptr: felt*}() {
    let (x) = foo(10);
    let (y) = foo(5);
    serialize_word(x + y);
    return ();
}
```

---

> Answers to this question are a part of the ✨ 17 days of Cairo Lang with Playground & Newton. ✨
> 

*Vote for your favorite answer - the best answer will win a $10 award. A new day – a new reward! During the next 17 days, our goal is to attract more developers to the Cairo language and to systematize the knowledge of Cairo lang. [Read rules](https://www.notion.so/17-days-of-Cairo-Lang-with-Newton-550dfcda6a2d449ca468be293c776578)*



Cairo Lang / StarkNet: What are Revoked references? What is alloc_locals?

Can we deploy kakarot zkEVM on StarkEx and then run multiple solidity dapps on top of it?

Deploying kakarot evm on starkEx

Does Kakarot zkEVM have a token?

# Is Kakarot equivalent to Arbitrum?

How does Kakarot compare to a more standard L2 such as Arbitrum / Optimism or zkSync 2.0 and Polygon zkEVM?

Is Kakarot equivalent to Arbitrum?

Where can I learn more about starknet?

What is starknet all about people

_This question was originally posted on [StarkNet Discord](https://www.newton.so/view?tags=discord)_

Where can I learn more about starknet?

How to transpile multiple contracts at once using [Nethermind's warp](https://github.com/NethermindEth/warp)?

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How can I interact with my contract on Starknet using starknetjs?

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Interact with your contract :

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