How to find the median of an array in JavaScript

Method: 1. Sort the array and find the array length; 2. Determine whether the array length is an even number or an odd number. If it is an even number, the median is "(array name[(array length)/ 2] Array name [((array length)/2) 1])/2", if it is an odd number, the median is "array name [(array length/2)-0.5]".

The operating environment of this tutorial: windows7 system, javascript version 1.8.5, Dell G3 computer.

The median is the middle number in a set of data arranged in order, representing a value in a sample, population or probability distribution, which can divide the value set into two equal upper and lower parts. For a finite set of numbers, you can sort all the observed values ​​and find the middle one as the median. If there is an even number of observations, the average of the two middle values ​​is usually taken as the median.

How to find the median of an array in JavaScript

Implementation idea:

• Yes Sort the array and then find the length of the array

• If the length of the array is an even number, then the median will be arr[(arr.length)/2] arr[((arr.length) /2) 1]/ 2.

• If the array length is odd, the median will be the middle element.

Implementation code:

function medianof2Arr(arr1) {
	var concat = arr1;
	concat = concat.sort(
		function(a, b) {
			return a - b
		});
	console.log(concat);
	var length = concat.length;
	if (length % 2 == 1) {
		// 如果长度是奇数
		console.log("中位数为： "+(concat[(length / 2) - 0.5]))
	} else {
		// 如果长度是偶数
		console.log("中位数为： "+(concat[length / 2]+concat[(length / 2) - 1]) / 2);

	}
}

arr1 = [1, 4, 7, 9,2]
medianof2Arr(arr1);

arr1 = [1, 4, 7, 9]
medianof2Arr(arr1);

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