You can use a struct where one member is the sign, and one is the value. ex:


`struct MyStruct:`


 `member is_negative : felt`


 `member value : felt`


`end`


ㅤ
_This answer was originally posted on [Triality](https://triality.org/question/1091)_

Cairo：我将如何存储负数然后将它们检索为负数？


struct MyStruct:


﻿  



 member is_negative : felt


﻿  



 member value : felt


﻿  



end


ㅤ
_This answer was originally posted on [Triality](https://triality.org/question/1091)_

Since all felts operate around modulo P, a negative number is naturally equal to some positive number modulo P. So if you are planning on just doing some addition or general math in your contract with that number, you should be fine. If you are bringing that number to the front end I can imagine that would be tricky. Then you might want to use a struct as mentioned in other answers or to save on storage costs, if you can afford not using the entire felt you can designate the first bit to be an indicator of positive or negative. 


﻿  



﻿  



ㅤ
_This answer was originally posted on [Triality](https://triality.org/question/1091)_

I am trying to store a negative number, and then on a function call, read it. But I only get the positive `felt` number.


ㅤ
_This question was originally posted on [Triality](https://triality.org/question/1091)_

Cairo: How would I store negative numbers then retrieve them as negatives?

How do I run a Pathfinder node?

Is Kakarot a Starkware project? 

Hey guys,

I am having issue with generating _abi.json file when I use namespace,
Please see example below.

Does someone know solution of how to generate _abi.json file when namespace is used? I really need help 🙏 

This code generates starknet_abi.json

%lang starknet
from starkware.cairo.common.cairo_builtins import HashBuiltin
from starkware.starknet.common.syscalls import get_caller_address

@External
   func store_name{syscall_ptr: felt, pedersen_ptr: HashBuiltin, range_check_ptr}(_count: felt) -> (even : felt) {
      alloc_locals;
      local even;

      let (caller) = get_caller_address();
      if (_count == 2) {
         even = 1;
      }
      return (even=even);
   }
=============================================================
This code does not generates starknet_abi.json (please see use of  namespace)

%lang starknet
from starkware.cairo.common.cairo_builtins import HashBuiltin
from starkware.starknet.common.syscalls import get_caller_address

namespace ToMoon {
@External
   func store_name{syscall_ptr: felt, pedersen_ptr: HashBuiltin, range_check_ptr}(_count: felt) -> (even : felt) {
      alloc_locals;
      local even;

      let (caller) = get_caller_address();
      if (_count == 2) {
         even = 1;
      }
      return (even=even);
   }
}



Issue with generating _abi.json file 

Is there a way/a tool that can automatically generate events for Cairo functions, since pretty much all of my events follow the same format


ㅤ
_This question was originally posted on [Triality](https://triality.org/question/221)_

Cairo Automatic Events

Is there any blockchain project contract supporting web2 scripts executable on VIa EVM?

I think it only one Tru (truebit)

Is there any blockchain project contract supporting web2 scripts executable on VIa EVM?

I am working through [ex03](https://github.com/starknet-edu/starknet-cairo-101/blob/main/contracts/ex03.cairo) of starknet-cairo-101 and I noticed that I was not being charged a gas fee for calling `increment_counter` multiple times back to back, it only charged me once. Does anyone know why this is happening?


ㅤ
_This question was originally posted on [Triality](https://triality.org/question/788)_

Did not have to pay gas fee when calling same function multiple times in Starknet?

I use `ec.getKeyPair("copy paste from argent x")` to initialize the account however i get the response is invalid, with respect to the public key

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

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Cairo: How would I store negative numbers then retrieve them as negatives?

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