Things you can do with Arrays

Get average value of items in a javascript array

const arrAvg = arr => arr.reduce((a,b) => a + b, 0) / arr.length
// arrAvg([20, 10, 5, 10]) -> 11.25

#javascript #nodejs

Append a Value to an Array

db.students.update(
   { _id: 1 },
   { $push: { scores: 89 } }
)

#javascript

How to Access Clicked Element From an Array With the Same Class

var allActionButtons = document.getElementsByClassName("action-buttons");

for (var i = 0; i < allActionButtons.length; i++) {

  allActionButtons[i].addEventListener('click', functionToRunWhenClicked, false);

}

var functionToRunWhenClicked = function {
  // Add some stuff here
}

#javascript #webdev #arrays #math

Function to find the minimum value in Javascript Arrays

const arrMin = arr => Math.min(...arr);
// arrMin([20, 10, 5, 10]) -> 5

#javascript #webdev #javascript #arrays #math

Function to find maximum value in javascript array

const arrMax = arr => Math.max(...arr);
// arrMax([20, 10, 5, 10]) -> 20

#javascript #webdev #arrays #math

Get sum of all values in javascript array

const arrSum = arr => arr.reduce((a,b) => a + b, 0)
// arrSum([20, 10, 5, 10]) -> 45

#javascript #mongoose #mongodb #mean

mongodb - How to find items using regex in Mongoose for partial text search

   var Person = mongoose.model('Person', yourSchema);
   // find each person with a name contains 'Ghost'
   Person.findOne({ "name" : { $regex: /Ghost/, $options: 'i' } },
          function (err, person) {
                 if (err) return handleError(err);
                 console.log('%s %s is a %s.', person.name.first, person.name.last, person.occupation);

   });