# Calculation inside a array of objects

I have the following array of objects like this

```let items = [
{
key: 1,
name: 'abc',
quanitity: 2,
rate: 10
},
{
key: 2,
name: 'abc 12',
quanitity: 4,
rate: 14
},
{
key: 3,
name: 'abc',
quanitity: 12,
rate: 12
} ]
```

now what I am doing is making a cart, now I want to display the total sum at the bottom based on the array. like this will return `2 * 10 + 4 * 14 + 12 * 12 = totalAmount`.

this is what I tried using forEach

```let dd = p.forEach((x) => {
let totalAmount = 0;

if (totalAmount === 0) {
let cal = Number(x.quantity) * Number(x.rate);
totalAmount = totalAmount + cal;
} else {
let cal2 = Number(x.quantity) * Number(x.rate);
totalAmount = cal2;
}
console.log("cal  sdda", totalAmount);

});
```

I used forEach but I am not getting the desired output, as well as used reduce but I know that won’t work. Any help

Using `Array#reduce`:

```const items = [
{ key: 1, name: 'abc', quanitity: "2", rate: "10" },
{ key: 2, name: 'abc 12', quanitity: "4", rate: "14" },
{ key: 3, name: 'abc', quanitity: "12", rate: "12" }
];

const totalAmount = items.reduce((total, { quanitity=0, rate=0 }) =>
total + (+quanitity * +rate)
, 0);

console.log(totalAmount);```

Using `Array#forEach`:

```const items = [
{ key: 1, name: 'abc', quanitity: "2", rate: "10" },
{ key: 2, name: 'abc 12', quanitity: "4", rate: "14" },
{ key: 3, name: 'abc', quanitity: "12", rate: "12" }
];

let totalAmount = 0;
items.forEach(({ quanitity=0, rate=0 }) =>
totalAmount += (+quanitity * +rate)
);

console.log(totalAmount);```