js foreach loop object code example

Example 1: foreach 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
*/

Example 2: foreach object javascript

const obj = {
  name: 'Jean-Luc Picard',
  rank: 'Captain'
};

// Prints "name Jean-Luc Picard" followed by "rank Captain"
Object.entries(obj).forEach(entry => {
  const [key, value] = entry;
  console.log(key, value);
});

Example 3: javascript foreach in object

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]);
    }
}

Example 4: javascript foreach object

function logArrayElements(element, index, array) {
  console.log('a[' + index + '] = ' + element)
}

// Notice that index 2 is skipped, since there is no item at
// that position in the array...
[2, 5, , 9].forEach(logArrayElements)
// logs:
// a[0] = 2
// a[1] = 5
// a[3] = 9