获取以分号分隔的字符串中的数字并计算平均jQuery

Question

I've got a string like so:

"45; 32; 31; 54"

I want to take these 4 numbers out of the string, then add them all together and divide by the number of numbers in the string in order to get the average.

How would I do this? There may be only 1 number (thus no need to average it), or there may be 10 numbers, I have no way of knowing how many numbers there will be in each one, except to say there will always be at least 1 number.

Answer 1

here is :

var s="45;32;31;54";
var s_array=s.split(';');
var sum=0;
var avarage=0;
for(var i =0;i<s_array.length;i++){

  sum+=parseInt(s_array[i]); 
}
avarage=sum/s_array.length;

Answer 2

Simple answer is :

var data = "45; 32; 31; 54"; //select the string
var arr = data.split('; '); //split the string
var sum = 0;

$.each(arr, function( index, value ) {
    sum += parseFloat(value);
});

var avg = sum / (arr.length);
console.log(avg)

Steps : 1. Define variable of string 2. Split it in to array. 3. Parse through array and add all the elements 4. Calculate Average :-)

Answer 3

Try

var str = "45; 32; 31; 54";
var arr = str.split(';'); //split into array
console.log(arr);

var sum = arr.reduce(function(a, b) { return +a + +b }); //Calculate sum
var avg = sum / arr.length; // Calculate avg
console.log(avg);

DEMO

Note: Used +Variable to convert variable to number

Answer 4

You don't need jQuery for this kind of tasks, and you can do everything in one line, using reduce :

var str = "45; 32; 31; 54";

var average = str.split("; ").reduce(function(avg, number, index) {
   return +avg + (number - avg) / (index + 1)
});

This is an incremental average, that is also useful if you have a lot of numbers and/or big numbers, so with regular averaging you could end up in overflow while you summing up the elements, this approach reduce that risk.

For the browser doesn't support reduce the documentation above provides a shim – nowadays modern browsers support ES5, and for older browsers this kind of shim should be a must-have.