solidity数组

在 Solidity 中，只有 storage 类型有动态数组。memory 类型的数组必须有固定长度，并且不允许使用push()来附加元素。

// SPDX-License-Identifier: GPL-3.0
pragma solidity >=0.7.0 <0.9.0;

contract MyArray {
    int256 [] intArr;
    int256 [3] intArr2; 
    int256 [2][] intArr3;

    constructor(){
        intArr3 = new int[2][](1);//2维数组,每个数组最多有2个元素,但只有一行
    }

    function addInt(int256 i) public {
        intArr.push(i);
        intArr2[0] = 100;
    }    

    function removeInt(uint index) public {
       delete intArr[index];
    }    

    function popInt(uint index) public {
        intArr[index] = intArr[intArr.length-1];
        intArr.pop();
    }

    function getIntArr()  public view returns (int256[] memory){
        return intArr;
    }

    function getIntArr2()  public view returns (int256){
        return intArr2[0];
    }

    function getLength() public view returns(uint){
        return intArr.length;
    }

    function newArr() public view returns(uint){
        int[] memory a = new int[](3);
        uint len = a.length;
        return len;
    }

    function setFlagPair(uint index) public {
        intArr3[index][0] = 1;
        intArr3[index][1] = 2;
        //intArr3[1][0] = 3;
    }

    function getFlagPair(uint index) public view returns(int,int ) {
        return (intArr3[index][0],intArr3[index][1]);
    }
}

const { expect } = require("chai");
const { ethers } = require("hardhat");

describe("contract", function () {
  it("test", async function () {
    const MyContract = await ethers.getContractFactory("MyArray");
    const myContract = await MyContract.deploy();
    await myContract.deployed();
    await myContract.addInt(1)
    await myContract.addInt(2)
    await myContract.addInt(3)
    arr = await myContract.getIntArr();
    console.log("result:",arr.toString())
    await myContract.removeInt(0)
    arr = await myContract.getIntArr();
    console.log("after remove:",arr.toString());
    len = await myContract.getLength();
    console.log("len:",len.toString());
    await myContract.popInt(0)
    arr = await myContract.getIntArr();
    console.log("after pop:",arr.toString());

    arr2 = await myContract.getIntArr2();
    console.log("arr2:",arr2.toString());    

    arrLen = await myContract.newArr();
    console.log("arrLen:",arrLen.toString());    

    await myContract.setFlagPair(0);
    i= await myContract.getFlagPair(0);
    console.log("i:",i.toString()); 
  });
});

  contract
result: 1,2,3
after remove: 0,2,3
len: 3
after pop: 3,2
arr2: 100
arrLen: 3
i: 1,2