How to find the total score and average in javascript

Implementation steps: 1. Create an array containing multiple data, the syntax "var arr=[num1,num2..numN];"; 2. Use forEach() to calculate the sum of the array elements, the syntax "var sum=0;function f(v){sum =v;}arr.forEach(f);"; 3. Use the length attribute to calculate the array length, the syntax is "arr.length;"; 4. Divide the total score by the array length You can get the average value with the syntax "sum/len".

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

In JavaScript, you can use arrays, the forEach() method and the length attribute to find the total score and average.

Implementation steps:

Step 1: Create an array containing multiple numeric data

var 数组名=[数值1,数值2..,数值N];

Step 2: Use forEach() to iterate the array to calculate the sum of the array elements (total score)

var sum = 0;
function f(value) {
sum += value;
}
数组对象.forEach(f);

Step 3: Use the length attribute to calculate the length of the array

var len=数组对象.length;

Step 4: Divide the total score by the array length

var avg=sum/len;

Implementation example:

var a = [10, 11, 12], sum = 0,len,avg;
console.log(a);
function f(value) {
sum += value;
}
a.forEach(f);
console.log("数组元素总和为："+sum);

len=a.length;
console.log("数组长度为："+len);

avg=sum/len;
console.log("数组平均数为："+avg);

Description:

1. forEach() method

forEach() method is used to call Each element of the array and passes the element to the callback function.

array.forEach(funtion callbackfn(value, index, array), thisValue)

funtion callbackfn(value, index, array): Required parameters, specify the callback function, can receive up to three parameters:

• value : The value of the array element.

• index: Numeric index of the array element.

• array: Array object containing the element.

thisValue: an omitted parameter, an object that can be referenced by this in the callback function. If thisArg is omitted, the value of this is undefined.

2. The length attribute

The length attribute can set or return the number of elements in the array.

Syntax

• Set the number of arrays:

array.length=number

• Return the number of arrays:

array.length

Return value:

• A number indicating the number of elements of the object in the array.

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