how to create a json array in javascript code example

Example 1: js create json array

var employees = {
    accounting: []
};

for(var i in someData) {    

    var item = someData[i];   

    employees.accounting.push({ 
        "firstName" : item.firstName,
        "lastName"  : item.lastName,
        "age"       : item.age 
    });
}

Example 2: json arrays

{
  "array": [{1,2,3,4,5,6}]
}