javascript foreach in object

JavaScript
const students = {
  adam: {age: 20},
  kevin: {age: 22},
};

Object.entries(students).forEach(student => {
  // key: student[0]
  // value: student[1]
  console.log(`Student: ${student[0]} is ${student[1].age} years old`);
});
/* Output:
Student: adam is 20 years old
Student: kevin is 22 years old
*/Object.keys(obj).forEach(function (key) {
   // do something with obj[key]
});for (var key in validation_messages) {
    // skip loop if the property is from prototype
    if (!validation_messages.hasOwnProperty(key)) continue;

    var obj = validation_messages[key];
    for (var prop in obj) {
        // skip loop if the property is from prototype
        if (!obj.hasOwnProperty(prop)) continue;

        // your code
        alert(prop + " = " + obj[prop]);
    }
}
Source

Also in JavaScript: