为什么在 solidity 中没有将 Null 初始化为无符号整数的概念？

Question

我正在编写代码，我的无符号整数值初始化为 0，如下所示

我的代码：

// SPDX-License-Identifier: UNLICENSED

pragma solidity >= 0.5.0 < 0.9.0;

contract PT_StateVariable

{

    uint256  public age ;
}

部署选项卡

但是当我试图给它一个NULL时，它报错了。

为什么在 Solidity 中没有使用 NULL 概念（就像在 C++ 中一样）？

Answer 1

在 Solidity 中 不存在 'NULL' 的概念，如 C++、C#、Java、... 文档是这样说的：

The concept of “undefined” or “null” values does not exist in Solidity, but newly declared variables always have a default value dependent on its type. To handle any unexpected values, you should use the revert function to revert the whole transaction, or return a tuple with a second bool value denoting success.

我建议您阅读文档中关于 declarations 的部分：

A variable which is declared will have an initial default value whose byte-representation is all zeros. The “default values” of variables are the typical “zero-state” of whatever the type is. For example, the default value for a bool is false. The default value for the uint or int types is 0. For statically-sized arrays and bytes1 to bytes32, each individual element will be initialized to the default value corresponding to its type. For dynamically-sized arrays, bytes and string, the default value is an empty array or string. For the enum type, the default value is its first member.

更多信息here。

为什么在 solidity 中没有将 Null 初始化为无符号整数的概念？

Why there's no concept of Null initialization to an unsigned integer in solidity?

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