---
title: addUpdateData
---
# addUpdateData <TitleWithCodeLink2 link="addUpdateData" />

add memo to an unsigned transaction.

## Usage

```javascript
const transaction = await tronWeb.transactionBuilder.addUpdateData(unsignedTransaction, memo, dataFormat, options);
```

## Parameters

| Argument            | Description                                                                                                                  | Type                      |
| ------------------- | ---------------------------------------------------------------------------------------------------------------------------- | ------------------------- |
| unsignedTransaction | Unsigned transaction object.                                                                                                 | JSON                      |
| memo                | Memo info                                                                                                                    | Utf8 string or Hex string |
| dataFormat          | Optional. The format of `memo` parameter. If the `memo` is hex string, this parameter should be `hex`. Default is `utf8`.    | `hex` or `utf8`           |
| options             | Optional. Options for `addUpdateData`. If `options.txLocal` is true, it will build locally. Default is `{ txLocal: false }`. | `{ txLocal: boolean }`    |

## Returns

The new transaction object. The added memo is stored in `raw_data.data` property.

**Note**:
- The Transaction hash(Transaction ID) will be changed after `addUpdateData` was executed as a new transaction object is generated.
- Please use the newly generated `transaction` for subsequent processes like `tronweb.trx.sign(transaction)` or `tronweb.trx.broadcast(transaction)`.
- From v6.0.4, `addUpdateData` will use `TronWeb.fromUtf8` to convert the provided data string-unless it starts with '0x'. If the resulting data string has an odd length, a '0' will be prepended to ensure even length.

## Example

```javascript
var txn = await tronWeb.transactionBuilder.sendTrx("TUoHaVjx7n5xz8LwPRDckgFrDWhMhuSuJM", 100, "TUznHJfHe6gdYY7gvWmf6bNZHuPHDZtowf");
var nexTxn = await tronWeb.transactionBuilder.addUpdateData(txn,"test");
var signedtxn = await tronWeb.trx.sign(nexTxn, privateKey);
console.log(nexTxn)
// output-start
{
  visible: false,
  txID: "8c3a4b4c20cfdf8df340905949a8241aee639492e0c4d73f1bf18847346444f1",
  raw_data: {
    contract: [ [Object] ],
    data: "74657374", // this is the HexString of memo
    expiration: 1628073045000,
    ref_block_bytes: "7254",
    ref_block_hash: "c45fff3a6a0347cc",
    timestamp: 1628072986845
  },
  raw_data_hex: "0a0272542208c45fff3a6a0347cc4088d8dc85b12f5204746573745a65080112610a2d747970652e676f6f676c65617069732e636f6d2f70726f746f636f6c2e5472616e73666572436f6e747261637412300a1541d0b69631440f0a494bb51f7eee68ff5c593c00f0121541ce8a0cf0c16d48bcf22825f6053248df653c89ca186470dd91d985b12f"
}
// output-end
```