freeCodeCamp/guide/english/certifications/javascript-algorithms-and-data-structures/object-oriented-programming/iterate-over-all-properties/index.md

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Iterate Over All Properties

Iterate Over All Properties

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Problem Explanation

The method is to use a for-in-loop to iterate through every property in the object. Inside the loop you then check if the property is a own-property or a prototype and place it in the ownProps[] array or the prototypeProps[] array. Remember to push properties to the beagle object and not the Dog object to pass all test cases.

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Solutions

Solution 1 (Click to Show/Hide)

function Dog(name) {
  this.name = name;
}

Dog.prototype.numLegs = 4;

let beagle = new Dog("Snoopy");

let ownProps = [];
let prototypeProps = [];

// Add your code below this line
for (let property in beagle) {
  if (Dog.hasOwnProperty(property)) {
    ownProps.push(property);
  } else {
    prototypeProps.push(property);
  }
}