function deepCopy(object) {
    if (object instanceof Date) {
        return new Date(+object);
    }
    var copy = Array.isArray(object) ? [] : {};
    for (var key in object) {
        if (object.hasOwnProperty(key)) {
            if (typeof object[key] == "object") {
                copy[key] = deepCopy(object[key]);
            } else {
                copy[key] = object[key];
            }
        }
    }
    return copy;
}
 
 
var a = { x: 1, y: 2, z: [[2, 2, 8], 2, 3], w: new Date(2014, 1, 1, 12, 0, 0) };
var b = deepCopy(a); // b — это отдельный объект
/*
console.log(a);
console.log(b);
*/
b.x = 10;
console.log(a.x); // 1
 
// a.z и b.z указывают на разные массивы:
b.z.push(4);
console.log(a.z); // [1, 2, 3]
 
// a.w и b.w независимы друг от друга
b.w.setFullYear(2015);
console.log(a.w.getFullYear()); // 2014
 
b.z[0].push(4);
console.log(a.z[0]);

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