How to restrict and show validation if JsonValue starts with "000" using JavaScript

Question

Need to compare two json objects and need to restrict if jsonValue is starts with "000" and have to show alert message. Please suggest me how to add validation,

var jsonData1 = [{"empId":341,"empSalary":"600000","empAdd":"000 abcd"}]
var jsonData2 = [{"empId":211,"empSalary":"600000","empAdd":"000 test"}]

for (var i = 0; i < jsonData1.length; i++) {
       for (var j = 0; j < jsonData2.length; j++) {       
        if ((jsonData1[i]['empAdd'] == '') || (jsonData2[j]['empAdd'] == '')) {
           alert("Invalid data"); 
         }
     }
}