hassanzohdy/collection/math-aggregation

const nums = collect([10, 20, 30]);
nums.sum();        // 60
nums.average();    // 20
nums.avg();        // 20 (alias)
nums.min();        // 10
nums.max();        // 30
nums.median();     // 20
const orders = collect([
  { total: { price: 100 } },
  { total: { price: 200 } },
]);
orders.sum("total.price");     // 300
orders.average("total.price"); // 150
orders.min("total.price");     // 100
orders.max("total.price");     // 200

collect(users).count(u => u.active);   // number of active users
collect(users).count("active");        // same, using a key string

collect(["a", "b", "a", "c"]).countValue("a"); // 2

collect(users).countBy("role");
// { admin: 3, user: 12, guest: 1 }

// Primitive
collect([1, 2, 3]).plus(10);       // [11, 12, 13]
collect([10, 20]).multiply(3);     // [30, 60]
collect([9, 6]).divide(3);         // [3, 2]
collect([10, 7]).modulus(3);       // [1, 1]
// Keyed field
collect([{ age: 20 }, { age: 30 }]).plus("age", 5);
// [{ age: 25 }, { age: 35 }]
collect(items).multiply("price", 1.2);  // apply 20% markup

collect([1, 2, 3]).increment();         // [2, 3, 4]
collect(items).increment("views");      // views + 1 on each item
collect(items).decrement("stock");      // stock - 1 on each item

collect([5, 10]).double();              // [10, 20]
collect([10, 20]).half();               // [5, 10]
collect(items).double("price");
collect(items).half("discount");

collect([1, 2, 3, 4]).even();           // [2, 4]
collect([1, 2, 3, 4]).odd();            // [1, 3]
collect(items).even("score");           // items where score is even

collect(["a","b","c","d"]).evenIndexes(); // ["a","c"] (indexes 0, 2)
collect(["a","b","c","d"]).oddIndexes();  // ["b","d"] (indexes 1, 3)