solidity智能合约[16]-固定长度数组

数组

内存中的一片连续区域

定义

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int[7] math;
bytes2[3] bytesTest;

赋值

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uint[5] public  grade =[1,2,3,4,5];

修改内容

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function init2() public {
bytesTest[1] = 0x6a6f;
}

返回数组

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function getArray2() public view returns(bytes2[3]){

return bytesTest;
}

获取数组长度

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function getlength() public view returns(uint){
return grade.length;

}

数组遍历求和

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function add() public view returns(uint){
uint sum= 0 ;
for(uint i = 0;i<5;i++){
sum+=grade[i];
}
return sum;
}

错误代码

固定数组不能修改大小和内容

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// function getlength2() public{
// grade.length =90;

// }

// function pushelement() public {

// grade.push(90);
// }

完整例子

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pragma solidity ^0.4.23;

contract arrayTest{


uint[5] public grade =[1,2,3,4,5];

int[7] math;
bytes2[3] bytesTest;

function init2() public {
bytesTest[1] = 0x6a6f;
}

function getArray2() public view returns(bytes2[3]){

return bytesTest;
}
function init() public {
grade[0] = 100;
grade[1] = 200;
}

function getArray() public view returns(uint[5]){

return grade;
}

function add() public view returns(uint){
uint sum= 0 ;
for(uint i = 0;i<5;i++){
sum+=grade[i];
}
return sum;
}

function getlength() public view returns(uint){
return grade.length;

}

// function getlength2() public{
// grade.length =90;

// }

// function pushelement() public {

// grade.push(90);
// }

}