var displayName="gnco\mahsa";
	
	var accountName=(displayName);	
	var requestUri = _spPageContextInfo.webAbsoluteUrl +
				  "/_api/SP.UserProfiles.PeopleManager/GetPropertiesFor(accountName=@v)?@v='i:0%23.w|"+accountName+"'";

	//execute AJAX request
	$.ajax({
		url: requestUri,
		type: "GET",
		headers: { "ACCEPT": "application/json;odata=verbose" },
		async: false,
		success: function (data) {
			var obj = data.d.UserProfileProperties; 
				if (typeof(obj) != "undefiend"){
				obj = obj.results
					$.each(obj,function(key,value){
						if (obj[key] == "PhoneWork"){
						alert(obj[key].value );
			
						}
					});
	
	
				}
			
		},
		error: function () {
			//alert("Failed to get details");                
		}
	});
	
	/_api/SP.UserProfiles.PeopleManager/GetPropertiesFor(accountName=@v)?@v=%27i:0%23.w|gnco\mahsa%27


///////////////////////////////
<script src="//code.jquery.com/jquery-1.11.3.min.js" type="text/javascript"></script>
<script type="text/javascript">
$(function () {
	var displayName="app";
	
	var accountName=GetAccountName(displayName);	
	var requestUri = _spPageContextInfo.webAbsoluteUrl +
				  "/_api/SP.UserProfiles.PeopleManager/GetUserProfilePropertyFor(accountName=@v,propertyName='Title')?@v='"+accountName+"'";

	//execute AJAX request
	$.ajax({
		url: requestUri,
		type: "GET",
		headers: { "ACCEPT": "application/json;odata=verbose" },
		async: false,
		success: function (data) {
			var userTitle=data.d.GetUserProfilePropertyFor;
			alert(userTitle);
		},
		error: function () {
			//alert("Failed to get details");                
		}
	});
});

function GetAccountName(displayName){
	var accountName="";
	var requestUri = _spPageContextInfo.webAbsoluteUrl +
				  "/_api/web/siteusers?$select=LoginName&$filter=Title eq '"+displayName+"'";
				  
	//execute AJAX request
	$.ajax({
		url: requestUri,
		type: "GET",
		headers: { "ACCEPT": "application/json;odata=verbose" },
		async: false,
		success: function (data) {
			if(data.d.results.length>0){
				accountName=data.d.results[0].LoginName.replace("#","%23");	
			}
			
		},
		error: function () {
			//alert("Failed to get details");                
		}
	});
	return accountName;
}
</script>


///////////////////////////
function gettingUserProfileByAccountName(accountName) {
 
 $.ajax({
 
 url: _spPageContextInfo.webAbsoluteUrl + "/_api/SP.UserProfiles.PeopleManager/GetPropertiesFor(accountName=@v)?@v='"+accountName+"'",
 
 headers: {
 
 "Accept": "application/json; odata=verbose"
 
 },
 
 async: false,
 
 contentType: "application/json; odata=verbose",
 
 success: function (data) {
 
 var results;
 
 if (data.d) {
 
 results = data.d.UserProfileProperties.results;
 
 for (i = 0; i < results.length; i++) {
 
 if (results[i].Key == "WorkEmail") {
 
 $('input[title="Requestor Email"]').val(results[i].Value);
 
 }
 
 if (results[i].Key == "WorkPhone") {
 
 $('input[title="Requestor Phone"]').val(results[i].Value);
 
 }
 
 }
 
 }
 
 }
 
 });
 
 }