javascript - Null check in the return statement

Question

When I have a null value in data.req, data.req.toLowerCase() is throwing an error. How can I check for a condition like

if(data.req === null) {
    //do nothing
} else { 
    data.req.toLowerCase().indexOf(searchTerms.req) !== -1
}

// How should i check for null for only data.req in the below mentioned return statement ?

return data.client.toLowerCase().indexOf(searchTerms.client) !== -1
    && data.req.toLowerCase().indexOf(searchTerms.req) !== -1;

// sample data

Data: [{req: "test", client: "client_01"},
{req: "now_test_01", client: "sample client"},
{req: "test", client: "client_01"},
{req: null, client: "sample client"},
{req: null, client: "client_01"},
{req: "now_test_018", client: "sample client"}]

Answer 1

You could use a default value, if the data.req is null.

(data.req || '').toLowerCase().indexOf(searchTerms.req) !== -1

Or with ES6

(data.req || '').toLowerCase().includes(searchTerms.req)