本质上来说，智能合约是一段程序，它以计算机指令的方式实现了传统合约的自动化处理。智能合约程序不只是一个可以自动执行的计算机程序，它本身就是一个系统参与者，对接收到的信息进行回应，可以接收和储存价值，也可以向外发送信息和价值。
简单讲，智能合约就是双方在区块链资产上交易时，触发执行的一段代码，这段代码就是智能合约。提前规定好合约的内容，当在满足触发合约条件的时候，程序就会自动执行合约内容。
在区块链应用开发过程中，需要调用您的智能合约，智能合约主要用于调用区块链。为提高基于链上的开发效率，BaaS平台提供了Cloud IDE智能合约开发工具和离线智能合约开发工具，帮助您快速实现智能合约的开发。
添加的代码中包括add()，sub()，mul()，sqr()和sqrt()函数：
contract mymath{
function sqrt(uint x)public view returns(uint y){
uint z=(x+1)/2;
y=x;
while(z<y){
y=z;
z=(x/z+z)/2;
}
}
function sqr(uint a)public view returns(uint){
uint c=a*a;
return c;
}
function mul(uint a,uint b)public view returns(uint){
uint c=a*b;
return c;
}
function sub(uint a,uint b)public view returns(uint){
return a-b;
}
function add(uint a,uint b)public view returns(uint){
uint c=a+b;
return c;
}}
现在编译我们的智能合约，并生成ABI(应用程序二进制接口)。通过ABI，我们可以创建智能合约中所有数据元素和函数。这通常用JSON格式定义。在我们的例子中，ABI是(可以从Remix中的ABI复制按钮中复制):
{
"inputs":[
{
"internalType":"uint256",
"name":"a",
"type":"uint256"
},
{
"internalType":"uint256",
"name":"b",
"type":"uint256"
}
],
"name":"add",
"outputs":[
{
"internalType":"uint256",
"name":"",
"type":"uint256"
}
],
"stateMutability":"view",
"type":"function"
},
{
"inputs":[
{
"internalType":"uint256",
"name":"a",
"type":"uint256"
},
{
"internalType":"uint256",
"name":"b",
"type":"uint256"
}
],
"name":"mul",
"outputs":[
{
"internalType":"uint256",
"name":"",
"type":"uint256"
}
],
"stateMutability":"view",
"type":"function"
},
{
"inputs":[
{
"internalType":"uint256",
"name":"a",
"type":"uint256"
}
],
"name":"sqr",
"outputs":[
{
"internalType":"uint256",
"name":"",
"type":"uint256"
}
],
"stateMutability":"view",
"type":"function"
},
{
"inputs":[
{
"internalType":"uint256",
"name":"x",
"type":"uint256"
}
],
"name":"sqrt",
"outputs":[
{
"internalType":"uint256",
"name":"y",
"type":"uint256"
}
],
"stateMutability":"view",
"type":"function"
},
{
"inputs":[
{
"internalType":"uint256",
"name":"a",
"type":"uint256"
},
{
"internalType":"uint256",
"name":"b",
"type":"uint256"
}
],
"name":"sub",
"outputs":[
{
"internalType":"uint256",
"name":"",
"type":"uint256"
}
],
"stateMutability":"view",
"type":"function"
}
