Solidity - Store random numbers to a dynamic array and return the array
0
I use remix IDE. When I call the function get number I got this 0: uint256:
How can I change it to return the dynamic array's numbers?
pragma solidity ^0.4.24;
contract dynamicarray {
uint public constant MaxNumber = 50;
uint numbers;
function randomnumber() public view returns (uint){
uint random = uint(sha3(block.timestamp)) % MaxNumber +1;
for(uint i = MaxNumber; i > numbers.length; i++){
numbers.push(random);
return random;
}
}
function getnumbers() public view returns(uint){
return numbers;
}
}
ethereum solidity smartcontracts
edited Nov 19 at 23:19
dferenc
4,487122030
asked Nov 19 at 20:16
Bandock
31
add a comment |
0
I use remix IDE. When I call the function get number I got this 0: uint256:
How can I change it to return the dynamic array's numbers?
pragma solidity ^0.4.24;
contract dynamicarray {
uint public constant MaxNumber = 50;
uint numbers;
function randomnumber() public view returns (uint){
uint random = uint(sha3(block.timestamp)) % MaxNumber +1;
for(uint i = MaxNumber; i > numbers.length; i++){
numbers.push(random);
return random;
}
}
function getnumbers() public view returns(uint){
return numbers;
}
}
ethereum solidity smartcontracts
edited Nov 19 at 23:19
dferenc
4,487122030
asked Nov 19 at 20:16
Bandock
31
The return statement is not the problem. Just tested on remix too. With a dynamic array. My guess is that your array is empty when you return it. You can check the size before you return it to see this is the case.
– nikos fotiadis
Nov 19 at 22:15
push() adds a new zero-initialized element to the dynamic array and returns the new length. To set the value of the new element you need to then directly assign it: solidity.readthedocs.io/en/develop/… Also, you're filling the entire array with the same (pseudo-random) number - is that the intention?
– sofend
Nov 19 at 23:28
@sofend The early return means that only one iteration of the loop will happen.
– smarx
Nov 20 at 4:13
@sofend i will replace the pseudo number later with Oracle or something i just stack to the basic structure for now
– Bandock
Nov 20 at 19:03
add a comment |
0
0
0
I use remix IDE. When I call the function get number I got this 0: uint256:
How can I change it to return the dynamic array's numbers?
pragma solidity ^0.4.24;
contract dynamicarray {
uint public constant MaxNumber = 50;
uint numbers;
function randomnumber() public view returns (uint){
uint random = uint(sha3(block.timestamp)) % MaxNumber +1;
for(uint i = MaxNumber; i > numbers.length; i++){
numbers.push(random);
return random;
}
}
function getnumbers() public view returns(uint){
return numbers;
}
}
ethereum solidity smartcontracts
edited Nov 19 at 23:19
dferenc
4,487122030
asked Nov 19 at 20:16
Bandock
31
I use remix IDE. When I call the function get number I got this 0: uint256:
How can I change it to return the dynamic array's numbers?
pragma solidity ^0.4.24;
contract dynamicarray {
uint public constant MaxNumber = 50;
uint numbers;
function randomnumber() public view returns (uint){
uint random = uint(sha3(block.timestamp)) % MaxNumber +1;
for(uint i = MaxNumber; i > numbers.length; i++){
numbers.push(random);
return random;
}
}
function getnumbers() public view returns(uint){
return numbers;
}
}
ethereum solidity smartcontracts
ethereum solidity smartcontracts
edited Nov 19 at 23:19
dferenc
4,487122030
asked Nov 19 at 20:16
Bandock
31
edited Nov 19 at 23:19
dferenc
4,487122030
asked Nov 19 at 20:16
Bandock
31
edited Nov 19 at 23:19
dferenc
4,487122030
edited Nov 19 at 23:19
dferenc
4,487122030
edited Nov 19 at 23:19
dferenc
4,487122030
4,487122030
asked Nov 19 at 20:16
Bandock
31
asked Nov 19 at 20:16
Bandock
31
asked Nov 19 at 20:16
Bandock
31
31
The return statement is not the problem. Just tested on remix too. With a dynamic array. My guess is that your array is empty when you return it. You can check the size before you return it to see this is the case.
– nikos fotiadis
Nov 19 at 22:15
push() adds a new zero-initialized element to the dynamic array and returns the new length. To set the value of the new element you need to then directly assign it: solidity.readthedocs.io/en/develop/… Also, you're filling the entire array with the same (pseudo-random) number - is that the intention?
– sofend
Nov 19 at 23:28
@sofend The early return means that only one iteration of the loop will happen.
– smarx
Nov 20 at 4:13
@sofend i will replace the pseudo number later with Oracle or something i just stack to the basic structure for now
– Bandock
Nov 20 at 19:03
add a comment |
The return statement is not the problem. Just tested on remix too. With a dynamic array. My guess is that your array is empty when you return it. You can check the size before you return it to see this is the case.
– nikos fotiadis
Nov 19 at 22:15
push() adds a new zero-initialized element to the dynamic array and returns the new length. To set the value of the new element you need to then directly assign it: solidity.readthedocs.io/en/develop/… Also, you're filling the entire array with the same (pseudo-random) number - is that the intention?
– sofend
Nov 19 at 23:28
@sofend The early return means that only one iteration of the loop will happen.
– smarx
Nov 20 at 4:13
@sofend i will replace the pseudo number later with Oracle or something i just stack to the basic structure for now
– Bandock
Nov 20 at 19:03
The return statement is not the problem. Just tested on remix too. With a dynamic array. My guess is that your array is empty when you return it. You can check the size before you return it to see this is the case.
– nikos fotiadis
Nov 19 at 22:15
The return statement is not the problem. Just tested on remix too. With a dynamic array. My guess is that your array is empty when you return it. You can check the size before you return it to see this is the case.
– nikos fotiadis
Nov 19 at 22:15
push() adds a new zero-initialized element to the dynamic array and returns the new length. To set the value of the new element you need to then directly assign it: solidity.readthedocs.io/en/develop/… Also, you're filling the entire array with the same (pseudo-random) number - is that the intention?
– sofend
Nov 19 at 23:28
push() adds a new zero-initialized element to the dynamic array and returns the new length. To set the value of the new element you need to then directly assign it: solidity.readthedocs.io/en/develop/… Also, you're filling the entire array with the same (pseudo-random) number - is that the intention?
– sofend
Nov 19 at 23:28
@sofend The early return means that only one iteration of the loop will happen.
– smarx
Nov 20 at 4:13
@sofend The early return means that only one iteration of the loop will happen.
– smarx
Nov 20 at 4:13
@sofend i will replace the pseudo number later with Oracle or something i just stack to the basic structure for now
– Bandock
Nov 20 at 19:03
@sofend i will replace the pseudo number later with Oracle or something i just stack to the basic structure for now
– Bandock
Nov 20 at 19:03
add a comment |
2 Answers
2
active
oldest
votes
1
Try this
pragma solidity ^0.4.24;
contract dynamicarray {
uint public constant MaxNumber = 50;
uint numbers;
function randomnumber() public returns (uint){
uint random = uint(keccak256(block.timestamp)) % MaxNumber +1;
for(uint i = MaxNumber; i > numbers.length; i++){
numbers.push(random);
return random;
}
}
function getnumbers() public view returns(uint){
return numbers;
}
}
answered Nov 20 at 9:54
Mahesh Rajput
2767
1
randomnumberdoesn't need to be payable.
– nikos fotiadis
Nov 20 at 10:33
Yeh. i updated answer
– Mahesh Rajput
Nov 20 at 10:37
Thank you very much both
– Bandock
Nov 20 at 18:55
add a comment |
1
The function is a view, so it can't modify state. Calling randomnumber() will return a value, but it won't change the numbers array.
Drop the view modifier from randomnumber(), and it will add one item to the array. (The early return will prevent the loop from repeating.)
answered Nov 20 at 4:15
smarx
48.1k45971
Thank you i get it now
– Bandock
Nov 20 at 19:00
Why is there a loop at all?
– sofend
Nov 20 at 22:13
add a comment |
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2 Answers
2
active
oldest
votes
2 Answers
2
active
oldest
votes
active
oldest
votes
active
oldest
votes
1
Try this
pragma solidity ^0.4.24;
contract dynamicarray {
uint public constant MaxNumber = 50;
uint numbers;
function randomnumber() public returns (uint){
uint random = uint(keccak256(block.timestamp)) % MaxNumber +1;
for(uint i = MaxNumber; i > numbers.length; i++){
numbers.push(random);
return random;
}
}
function getnumbers() public view returns(uint){
return numbers;
}
}
answered Nov 20 at 9:54
Mahesh Rajput
2767
1
randomnumberdoesn't need to be payable.
– nikos fotiadis
Nov 20 at 10:33
Yeh. i updated answer
– Mahesh Rajput
Nov 20 at 10:37
Thank you very much both
– Bandock
Nov 20 at 18:55
add a comment |
1
Try this
pragma solidity ^0.4.24;
contract dynamicarray {
uint public constant MaxNumber = 50;
uint numbers;
function randomnumber() public returns (uint){
uint random = uint(keccak256(block.timestamp)) % MaxNumber +1;
for(uint i = MaxNumber; i > numbers.length; i++){
numbers.push(random);
return random;
}
}
function getnumbers() public view returns(uint){
return numbers;
}
}
answered Nov 20 at 9:54
Mahesh Rajput
2767
1
randomnumberdoesn't need to be payable.
– nikos fotiadis
Nov 20 at 10:33
Yeh. i updated answer
– Mahesh Rajput
Nov 20 at 10:37
Thank you very much both
– Bandock
Nov 20 at 18:55
add a comment |
1
1
1
Try this
pragma solidity ^0.4.24;
contract dynamicarray {
uint public constant MaxNumber = 50;
uint numbers;
function randomnumber() public returns (uint){
uint random = uint(keccak256(block.timestamp)) % MaxNumber +1;
for(uint i = MaxNumber; i > numbers.length; i++){
numbers.push(random);
return random;
}
}
function getnumbers() public view returns(uint){
return numbers;
}
}
answered Nov 20 at 9:54
Mahesh Rajput
2767
Try this
pragma solidity ^0.4.24;
contract dynamicarray {
uint public constant MaxNumber = 50;
uint numbers;
function randomnumber() public returns (uint){
uint random = uint(keccak256(block.timestamp)) % MaxNumber +1;
for(uint i = MaxNumber; i > numbers.length; i++){
numbers.push(random);
return random;
}
}
function getnumbers() public view returns(uint){
return numbers;
}
}
answered Nov 20 at 9:54
Mahesh Rajput
2767
edited Nov 20 at 10:50
answered Nov 20 at 9:54
Mahesh Rajput
2767
answered Nov 20 at 9:54
Mahesh Rajput
2767
answered Nov 20 at 9:54
Mahesh Rajput
2767
2767
1
randomnumberdoesn't need to be payable.
– nikos fotiadis
Nov 20 at 10:33
Yeh. i updated answer
– Mahesh Rajput
Nov 20 at 10:37
Thank you very much both
– Bandock
Nov 20 at 18:55
add a comment |
1
randomnumberdoesn't need to be payable.
– nikos fotiadis
Nov 20 at 10:33
Yeh. i updated answer
– Mahesh Rajput
Nov 20 at 10:37
Thank you very much both
– Bandock
Nov 20 at 18:55
1
1
randomnumber doesn't need to be payable.– nikos fotiadis
Nov 20 at 10:33
randomnumber doesn't need to be payable.– nikos fotiadis
Nov 20 at 10:33
Yeh. i updated answer
– Mahesh Rajput
Nov 20 at 10:37
Yeh. i updated answer
– Mahesh Rajput
Nov 20 at 10:37
Thank you very much both
– Bandock
Nov 20 at 18:55
Thank you very much both
– Bandock
Nov 20 at 18:55
add a comment |
1
The function is a view, so it can't modify state. Calling randomnumber() will return a value, but it won't change the numbers array.
Drop the view modifier from randomnumber(), and it will add one item to the array. (The early return will prevent the loop from repeating.)
answered Nov 20 at 4:15
smarx
48.1k45971
Thank you i get it now
– Bandock
Nov 20 at 19:00
Why is there a loop at all?
– sofend
Nov 20 at 22:13
add a comment |
1
The function is a view, so it can't modify state. Calling randomnumber() will return a value, but it won't change the numbers array.
Drop the view modifier from randomnumber(), and it will add one item to the array. (The early return will prevent the loop from repeating.)
answered Nov 20 at 4:15
smarx
48.1k45971
Thank you i get it now
– Bandock
Nov 20 at 19:00
Why is there a loop at all?
– sofend
Nov 20 at 22:13
add a comment |
1
1
1
The function is a view, so it can't modify state. Calling randomnumber() will return a value, but it won't change the numbers array.
Drop the view modifier from randomnumber(), and it will add one item to the array. (The early return will prevent the loop from repeating.)
answered Nov 20 at 4:15
smarx
48.1k45971
The function is a view, so it can't modify state. Calling randomnumber() will return a value, but it won't change the numbers array.
Drop the view modifier from randomnumber(), and it will add one item to the array. (The early return will prevent the loop from repeating.)
answered Nov 20 at 4:15
smarx
48.1k45971
answered Nov 20 at 4:15
smarx
48.1k45971
answered Nov 20 at 4:15
smarx
48.1k45971
answered Nov 20 at 4:15
smarx
48.1k45971
48.1k45971
Thank you i get it now
– Bandock
Nov 20 at 19:00
Why is there a loop at all?
– sofend
Nov 20 at 22:13
add a comment |
Thank you i get it now
– Bandock
Nov 20 at 19:00
Why is there a loop at all?
– sofend
Nov 20 at 22:13
Thank you i get it now
– Bandock
Nov 20 at 19:00
Thank you i get it now
– Bandock
Nov 20 at 19:00
Why is there a loop at all?
– sofend
Nov 20 at 22:13
Why is there a loop at all?
– sofend
Nov 20 at 22:13
add a comment |
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The return statement is not the problem. Just tested on remix too. With a dynamic array. My guess is that your array is empty when you return it. You can check the size before you return it to see this is the case.
– nikos fotiadis
Nov 19 at 22:15
push() adds a new zero-initialized element to the dynamic array and returns the new length. To set the value of the new element you need to then directly assign it: solidity.readthedocs.io/en/develop/… Also, you're filling the entire array with the same (pseudo-random) number - is that the intention?
– sofend
Nov 19 at 23:28
@sofend The early return means that only one iteration of the loop will happen.
– smarx
Nov 20 at 4:13
@sofend i will replace the pseudo number later with Oracle or something i just stack to the basic structure for now
– Bandock
Nov 20 at 19:03