宅D嘉
有著十年以上的軟體開發經驗,喜歡投資理財,目前喜歡研究區塊鏈相關,了解虛擬貨幣投資或者是區塊鏈開發,喜歡把複雜的東西簡單化,樂於分享我的理財投資生活。
// SPDX-License-Identifier: MITpragma solidity ^0.8.13;library SafeMath {//數字新增檢查function add(uint x, uint y) internal pure returns(uint) {uint result = x + y;require(result >= x, "Overflow!");return result;}}library Array {//陣列移除某內容function remove(uint[] storage arr, uint index) public {arr[index] = arr[arr.length -1];arr.pop();}}
// SPDX-License-Identifier: MITpragma solidity ^0.8.13;import "./Library.sol";contract TestSafeMath {using SafeMath for uint;//引用library到uint屬性內function testAdd(uint x, uint y) public pure returns (uint) {uint result = x.add(y);//SafeMath.add(x,y);return result;}}contract TestArray {using Array for uint[];//引用Libraryuint[] public testArr;function testArrayRemove() public {testArr.push(1);testArr.push(2);testArr.push(3);//testArr = [1,2,3]testArr.remove(1);//testArr = [1,3]//驗證assert(testArr.length == 2);assert(testArr[0] == 1);assert(testArr[1] == 3);}}