`connectors` should come from `useConnectors`

This example shows how to use it https://apibara.github.io/starknet-react/hooks/useConnectors

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

Newton

```
...
const { available, connect, refresh, disconnect } = useConnectors()

    const connectors = [
      new InjectedConnector({ options: { id: "argentX" } })
    ];

return(
  <button onClick={() => connect(connectors[0])}>
    Connect {connectors[0].id()}
  </button>
)
```
any idea why this code doesnt connect to argentX in brave?

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

Any idea why this code doesn’t connect to argentX in brave?

Everyone knows that secure code is essential. Can someone explain what is reentrancy?
I am curious about the reentrancy attack in StarkNet – is it a problem in Cairo Language and how to protect my smart contract from this attack?

How to protect my contract from reentrancy in Cairo Language / StarkNet?

What’s the difference between Account Abstraction (AA) and Externally Owned Accounts (EOA)?

---

This question is participating in [Newton Bounties | Incentivized Test Program](https://www.notion.so/Newton-Bounties-Incentivized-Test-Program-94322ad48e7d40a3adcf36f6b26174cd) Every verified valid question gets $10 USDC (mainnet)

What’s the difference between Account Abstraction (AA) and Externally Owned Accounts (EOA)?

when i am planing to send a token ,it always goes wrong

how to send token 

I have a question about how to print "Hello World" in Cairo 1. How do I log/print ?

How do I log/print in Cairo 1.0?

Hey, is there anyway to debug Cairo contracts in hardhat environment? Something like hardhat console in Solidity?

Hey, is there anyway to debug Cairo contracts in hardhat environment? Something like hardhat console in solidity

Hello! This is day 12 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 “Structs.  Perhaps you can help me?

```
// In this challenge you're going to implement a stack using a linked list.
//
// Add the missing code so that main() runs successfully.

from starkware.cairo.common.registers import get_fp_and_pc

struct Node {
    // A pointer to the next node in the stack.
    next: Node*,

    // The value of the node.
    value: felt,

    // The number of elements in the stack.
    size: felt,
}

// Returns an empty stack.
func empty_stack() -> (stack: Node*) {
    alloc_locals;
    local new_node: Node;
    assert new_node.next = cast(0, Node*);
    assert new_node.value = 0;
    assert new_node.size = 0;

    // The usage of get_fp_and_pc() here is necessary in order
    // to access the address of a local variable (&new_node).
    // You can read more about get_fp_and_pc() [here](https://cairo-lang.org/docs/how_cairo_works/functions.html#retrieving-registers).
    let (local __fp__, _) = get_fp_and_pc();
    return (stack=&new_node);
}

// Adds a node to the top of the stack.
// Returns the updated stack (since Cairo is immutable, you can still use the
// old copy of the stack).
func push(stack: Node*, value: felt) -> (stack: Node*) {
    alloc_locals;
    local new_node: Node;
    // Fix and uncomment below.
    // assert new_node.next = ...
    // assert new_node.value = ...
    // assert new_node.size = ...

    let (__fp__, _) = get_fp_and_pc();
    return (stack=&new_node);
}

// Removes the top element of the stack.
// Returns the updated stack and the element that was removed.
func pop(stack: Node*) -> (stack: Node*, value: felt) {
    return (stack=stack.next, value=stack.value);
}

// Returns the value of the n-th element from the top of the stack.
func stack_at(stack: Node*, n: felt) -> (value: felt) {
    if (n == 0) {
        // Add your code here.
    }

    // Add your code here.
}

func main() -> () {
    alloc_locals;
    // Start with an empty stack.
    let (stack) = empty_stack();
    // Push 1, 10, 100.
    let (stack) = push(stack, 1);
    let (stack) = push(stack, 10);
    let (local stack) = push(stack, 100);

    // Check the size of the stack.
    assert stack.size = 3;

    // Query the stack at indices 0, 1 and 2.
    let (value) = stack_at(stack, 0);
    assert value = 100;
    let (value) = stack_at(stack, 1);
    assert value = 10;
    let (value) = stack_at(stack, 2);
    assert value = 1;

    // Pop the top 2 values (100 and 10) and push 1000.
    let (stack, value) = pop(stack);
    assert value = 100;
    let (stack, value) = pop(stack);
    assert value = 10;
    let (local stack) = push(stack, 1000);

    // Query the stack at indices 0 and 1.
    let (value) = stack_at(stack, 0);
    assert value = 1000;
    let (value) = stack_at(stack, 1);
    assert value = 1;

    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)*

How to create Structs in Cairo Lang for StarkNet?

Hi, I'm using pytest for testing cairo contract. I found that a simple starknet setup and initial call for contract cost 34 seconds. Is there a way to accelerate test?

upd: yes, [this works](https://www.notion.so/Hi-I-m-using-pytest-for-testing-cairo-contract-I-found-that-a-simple-starknet-setup-and-initial-ca-db2282fc02f2463aadaf63eac655df6f). but I found that compiling contract cost 7s and deploying contract cost 25s. These two operations are the most time-consuming

Popular tags

Any idea why this code doesn’t connect to argentX in brave?

1 answers

Your answer

Related

You may find useful