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JavaScript - find closest number to given value in array
3 points
In this article, we would like to show you how to find the closest number in an array to the given value in JavaScript.
Quick solution:
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const goal = 4;2
const numbers = [1, 2, 8, 9];3
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const closest = numbers.reduce((prev, curr) => {5
return Math.abs(curr - goal) < Math.abs(prev - goal) ? curr : prev;6
});7
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console.log(closest); // 2
In this example, we use Array reduce() method with Math.abs() to find the closest number to the goal in numbers array by comparing absolute values of the differences.
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const findClosest = (array, goal) => {2
return array.reduce((prev, curr) => {3
return Math.abs(curr - goal) < Math.abs(prev - goal) ? curr : prev;4
});5
};6
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// Usage example:9
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const goal = 4;11
const numbers = [1, 2, 8, 9];12
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const closestValue = findClosest(numbers, goal);14
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console.log('value: ' + closestValue); // 2xxxxxxxxxx1
const findClosest = (array, goal) => {2
if (array.length > 0) {3
let index = 0;4
let error = Math.abs(array[0] - goal);5
for (let i = 1; i < array.length; ++i) {6
const e = Math.abs(array[i] - goal);7
if (e < error) {8
index = i;9
error = e;10
}11
}12
return index;13
}14
return -1;15
};16
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// Usage example:19
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const goal = 4;21
const numbers = [1, 2, 8, 9];22
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const closestIndex = findClosest(numbers, goal);24
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if (closestIndex !== -1) {26
const closestValue = numbers[closestIndex];27
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console.log('index: ' + closestIndex); // 229
console.log('value: ' + closestValue); // 830
}
