How to use array in rest API for getting items based on array values

Question

I have array with id's of list items so I want those items from list using rest.

I found this

/_api/web/lists/getByTitle(listTitle)/items?$filter=(ID eq 1) or (ID
 eq 2) or (ID eq 3)

So in this I need to use array values instead of hard coded values.

How would I do it if i have an array as array[j]

Answer 1

Write some javascript to build your $filter and then append it to the query url.

function getFilter(ids) {
    var idFilter = "ID eq ";
    var filter = "";
    for (var i = 0; i < ids.length; i++) {
        if (i == ids.length - 1) {
            filter += idFilter + ids[i];
        } else {
            filter += idFilter + ids[i] + " or ";
        }
    }
    return filter;
}

Now assume that name of id's array is ids:

var ids = [1, 2, 3];

Now call the above function

var filterById = getFilter(ids);

Output: "ID eq 1 or ID eq 2 or ID eq 3"

Now change the query url like

"/_api/web/lists/getByTitle(listTitle)/items?$filter='"+ filterById +"'";

Check this jsbin how getFilter() works.

Answer 2

Adding this from the comments because I found it very useful and almost missed it:

var filterById = 'ID eq ' + ids.join(' or ID eq ');
var url = "/_api/web/lists/getByTitle(listTitle)/items?$filter='"+ filterById;

You can make it even more generic like this:

function contains(prop, values) {
    return prop + ' eq ' + values.join(' or ' + prop + ' eq ');
}

Answer 3

Building on the two previous answers, I feel it's a bit easier to read it this way:

var ids = [1, 2, 3];
var filters = ids.map(function(id){
    return 'ID eq ' + id;
}
var url = "/_api/web/lists/getByTitle(listTitle)/items?$filter=" + filters.join(' or ');

or in ES6:

var ids = [1, 2, 3];
var filters = ids.map(id => `ID eq ${id}`);
var url = `/_api/web/lists/getByTitle(listTitle)/items?$filter=${filters.join(' or ')}`;