Replicate items using JavaScript

While delving into the core concepts of JavaScript Objects, I came across a code snippet for copying objects:

function copy(a, b) {
    for (prop in b) {
        a[prop] = b[prop];
    }
    return a;
}

This function will replace the properties of object a with the corresponding properties from object b.

If we then use the following code:

function union(a, b) {
    return copy(copy({}, a), b);
}

The explanation provided mentions that the union function will prioritize the values from object a if both objects have identical properties. Can someone help clarify this for me?

Answer №1

Perhaps there is an error in the book, possibly just a typo.

If both a and b share the same properties, the value from a will be utilized.

After the most recent invocation of copy, ensure that you pass b as the second argument. In this case, if a and b have matching properties, union will use the value from b.

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