FilterInJS

FilterInJS.js

const transActionsForMike = [ {Name: "Bike", Cost: 5000}, 
                              {Name: "Apple Music", Cost: 20}, 
                              {Name: "Cook Book", Cost: 30},
                              {Name: "Azure Hosting", Cost: 60}, 
                              {Name: "Phone Bill", Cost: 70}];

// As seen in Reduce and Map, we can add more elements into the 
// anonymous functions such as the index and the whole array

// filter gives us each element in the array. We then have to return 
// "true" to keep it in, or "false" to get rid of it.

// In the case below we are keeping the element in the new array we are returning
// if it's cost property is less than 100 or more than 20
let MikesSmallTransactions = transActionsForMike.filter((ele) => {
    return ele.Cost < 100 && ele.Cost > 20;
});

console.log(MikesSmallTransactions); 
// MikesSmallTransactions is now: [ { Name: 'Cook Book', Cost: 30 },
//                                  { Name: 'Azure Hosting', Cost: 60 },
//                                  { Name: 'Phone Bill', Cost: 70 } ]