# How can I calculate the sum of specific property values in an array of objects in JavaScript?Alex Kconst t="undefined"!=typeof HTMLImageElement&&"loading"in HTMLImageElement.prototype;if(t){const t=document.querySelectorAll("img[data-main-image]");for(let e of t){e.dataset.src&&(e.setAttribute("src",e.dataset.src),e.removeAttribute("data-src")),e.dataset.srcset&&(e.setAttribute("srcset",e.dataset.srcset),e.removeAttribute("data-srcset"));const t=e.parentNode.querySelectorAll("source[data-srcset]");for(let e of t)e.setAttribute("srcset",e.dataset.srcset),e.removeAttribute("data-srcset");e.complete&&(e.style.opacity=1,e.parentNode.parentNode.querySelector("[data-placeholder-image]").style.opacity=0)}}

To calculate the sum of specific property values in an array of objects in JavaScript, you can use various approaches, such as using a loop, the`reduce()` method, or a combination of`map()` and`reduce()`. Here are examples of each approach: 1. Using a loop:

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function calculateSum(objects, property) {
let sum = 0;
for (let i = 0; i < objects.length; i++) {
sum += objects[i][property];
}
return sum;
}
``````

In this example, the`calculateSum` function takes an array of objects,`objects`, and the property name,`property`, as parameters. It uses a loop to iterate over each object and adds the corresponding property value to the`sum` variable. Finally, it returns the calculated sum. 2. Using the`reduce()` method:

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function calculateSum(objects, property) {
return objects.reduce((sum, obj) => sum + obj[property], 0);
}
``````

The`reduce()` method iterates over the array, accumulating a value (the`sum`) based on each object's property value. It takes a callback function as the first argument, which receives the accumulator (sum) and the current object (obj). The callback function adds the property value to the`sum`, starting from an initial value of 0. 3. Using`map()` and`reduce()`:

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function calculateSum(objects, property) {
return objects
.map((obj) => obj[property])
.reduce((sum, value) => sum + value, 0);
}
``````

In this approach, the`map()` method is used to create a new array containing only the property values of the objects. Then, the`reduce()` method calculates the sum of the values in the newly created array. Here's an example usage of the`calculateSum` function:

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const items = [
{ name: 'Item 1', price: 10 },
{ name: 'Item 2', price: 20 },
{ name: 'Item 3', price: 30 },
];

const total = calculateSum(items, 'price');
console.log(total); // Output: 60
``````

In this example, the`calculateSum` function is called with an array of objects (items) and the property name`'price'`. It calculates the sum of the`price` property for each object in the array, resulting in a total of 60. You can modify the`calculateSum` function according to your specific needs, such as handling edge cases or validating the input.