Setting default value for person column to current user in SharePoint 2013 using REST

Add a content editor WebPart to the New form of custom list and add the below code, replace the ID of your column highlighted yellow SetUserFieldValue function parameter to your people picker column name.

<script src="//ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>

<script type="text/javascript">

$(document).ready(function () {

var userid = _spPageContextInfo.userId;

function GetCurrentUser() {

var requestUri = _spPageContextInfo.webAbsoluteUrl + "/_api/web/getuserbyid(" + userid + ")";

var requestHeaders = { "accept" : "application/json;odata=verbose" };

$.ajax({

url : requestUri,

contentType : "application/json;odata=verbose",

headers : requestHeaders,

success : onSuccess,

error : onError

});

}

function onSuccess(data, request){

var loginName = data.d.Title;

SetUserFieldValue("people",loginName);

}

function onError(error) {

//alert(error);

}

function SetUserFieldValue(fieldName, userName) {

var _PeoplePicker = $("div[title='" + fieldName + "']");

var _PeoplePickerTopId = _PeoplePicker.attr('id');

var _PeoplePickerEditer = $("input[title='" + fieldName + "']");

_PeoplePickerEditer.val(userName);

var _PeoplePickerOject = SPClientPeoplePicker.SPClientPeoplePickerDict[_PeoplePickerTopId];

_PeoplePickerOject.AddUnresolvedUserFromEditor(true);

}

GetCurrentUser();

});

</script>