How Can I Iterate and Retrieve Keys and Values from a JavaScript Object?

Iterating and Retrieving Keys and Values from JavaScript Objects

When dealing with JavaScript objects, it's essential to loop through their elements to access and process their keys and values. Here's how you can accomplish this task effortlessly:

Using the for-in Loop

The most common method is to use the for-in loop, as demonstrated below:

var p = {
    "p1": "value1",
    "p2": "value2",
    "p3": "value3"
};

for (var key in p) {
    // Ensure the key is a direct property of the object using hasOwnProperty
    if (p.hasOwnProperty(key)) {
        console.log(key + " -> " + p[key]);
    }
}

Ensuring True Property Ownership

It's crucial to verify that the keys you're accessing belong to the object directly. JavaScript allows for inheritance from prototypes, which can lead to properties not owned by the object itself. To ensure true ownership, use the hasOwnProperty method:

for (var key in p) {
    if (p.hasOwnProperty(key)) {
        // Key is an actual property of the object
    }
}

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