I am converting array of hash into a string then store it in the smart contract. It is throwing error as;

transact to Test.set errored: Error encoding arguments: SyntaxError: Unexpected number in JSON at position 46

Array: [0xca35b7d915458ef540ade6068dfe2f44e8fa733c,0xca35b7d915458ef540ade6068dfe2f44e8fa733c,0xca35b7d915458ef540ade6068dfe2f44e8fa733c,0xca35b7d915458ef540ade6068dfe2f44e8fa733c,0xca35b7d915458ef540ade6068dfe2f44e8fa733c,0xca35b7d915458ef540ade6068dfe2f44e8fa733c,0xca35b7d915458ef540ade6068dfe2f44e8fa733c,0xca35b7d915458ef540ade6068dfe2f44e8fa733c,0xca35b7d915458ef540ade6068dfe2f44e8fa733c,0xca35b7d915458ef540ade6068dfe2f44e8fa733c]

It is working fine when length of array is 2, more than this it is not working.

pragma solidity ^0.4.24;

contract Test {
   string public t;
   function set(string _t) public {
       t = _t;

Conversion from array to string is handle by a separate javascript.

1 Answer 1


Not sure exactly where you are going wrong since you do not share the JavaScript which converts the array to a string, but in theory what you are doing should be just fine.

I recommend that you use the JSON.stringify() function to convert your array into a proper string.

>> let arr = new Array(10).fill("0xca35b7d915458ef540ade6068dfe2f44e8fa733c")

>> arr
Array(10) [ "0xca35b7d915458ef540ade6068dfe2f44e8fa733c", "0xca35b7d915458ef540ade6068dfe2f44e8fa733c", "0xca35b7d915458ef540ade6068dfe2f44e8fa733c", "0xca35b7d915458ef540ade6068dfe2f44e8fa733c", "0xca35b7d915458ef540ade6068dfe2f44e8fa733c", "0xca35b7d915458ef540ade6068dfe2f44e8fa733c", "0xca35b7d915458ef540ade6068dfe2f44e8fa733c", "0xca35b7d915458ef540ade6068dfe2f44e8fa733c", "0xca35b7d915458ef540ade6068dfe2f44e8fa733c", "0xca35b7d915458ef540ade6068dfe2f44e8fa733c" ]

>> JSON.stringify(arr)

This last string should have no such syntax errors. To undo the stringify, just use JSON.parse().

  • Thank you it works. Actually I was using toString() for conversion. Don't know what exactly is the difference between 2. Nov 23, 2018 at 7:13
  • Thank you the string in your it works. How it is adding '\' ? When I am doing JSON.stringify() it is just making it in string format, no '\' were there and without those '\' it is giving the same error. Nov 23, 2018 at 7:26
  • The backslash is an "escape character" telling the JavaScript to parse the following character as a character, rather than code syntax. This is how you can use quotation marks within a string. JSON.stringify and JSON.parse are standard in JavaScript, and should pretty much always be your go to when doing things like this. Nov 23, 2018 at 11:11

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