To get the item count in a specific list view, firstly get the list view CAML Query, then use this CAML Query with Post Request in Rest API to return items, here is a code snippet for your reference:
<script type="text/javascript">
getListItemsForView(_spPageContextInfo.webAbsoluteUrl,'ABC','XYZ')
.done(function(data)
{
var itemsCount = data.d.results.length;
alert(itemsCount);
})
.fail(
function(error){
console.log(JSON.stringify(error));
});
function getListItemsForView(webUrl,listTitle,viewTitle)
{
var viewQueryUrl = webUrl + "/_api/web/lists/getByTitle('" + listTitle + "')/Views/getbytitle('" + viewTitle + "')/ViewQuery";
return getJson(viewQueryUrl).then(
function(data){
var viewQuery = data.d.ViewQuery;
return getListItems(webUrl,listTitle,viewQuery);
});
}
function getJson(url)
{
return $.ajax({
url: url,
type: "GET",
contentType: "application/json;odata=verbose",
headers: {
"Accept": "application/json;odata=verbose"
}
});
}
function getListItems(webUrl,listTitle, queryText)
{
var viewXml = '<View><Query>' + queryText + '</Query></View>';
var url = webUrl + "/_api/web/lists/getbytitle('" + listTitle + "')/getitems";
var queryPayload = {
'query' : {
'__metadata': { 'type': 'SP.CamlQuery' },
'ViewXml' : viewXml
}
};
return $.ajax({
url: url,
method: "POST",
data: JSON.stringify(queryPayload),
headers: {
"X-RequestDigest": $("#__REQUESTDIGEST").val(),
"Accept": "application/json; odata=verbose",
"content-type": "application/json; odata=verbose"
}
});
}
</script>
Reference:
Using REST to fetch SharePoint View Items