如何从数组中拆分和获取选择数据

I have array like this in JavaScript

我在JavaScript中有这样的数组

var a = [1,2,3,4,5,"4","12","2",6,7,"4",3,"2"];

My questions are

我的问题是

How do I split the array to change, (comma) to ";"

如何拆分要更改的数组,(逗号)为“;”
How do I return the number of strings in the array as well as return total value regardless of variable type.

如何返回数组中的字符串数以及返回总值而不管变量类型如何。
How do I return the average value (regardless of variable type again)

如何返回平均值(不管变量类型如何)

5 个解决方案

#1

Answering Question 1

回答问题1

1.Convert it to a string

1.将其转换为字符串

var x=a.toString();

2.Perform a global replace

2.执行全局替换

var y= x.replace(/,/g,";");

3.This gives you "1;2;3;4;5;4;12;2;6;7;4;3;2"

这给你“1; 2; 3; 4; 5; 4; 12; 2; 6; 7; 4; 3; 2”

For Question 2 Simply use the a.length method.This will give you the total number of elements.I'm not sure about the String elements part.

问题2只需使用a.length方法。这将为您提供元素总数。我不确定String元素部分。

#2

Change array separator:

更改数组分隔符:

a.join(';');

as referenced here

这里引用

Number of strings in array:

数组中的字符串数:

var stringCount = 0;
for (var i = 0; i < a.length; i++){
  if (typeof a[i] === 'string'){
    stringCount++;
  }
}

alert("The number of strings is: " + stringCount);

Test it here: https://jsfiddle.net/6c42nugy/2/

在这里测试:https://jsfiddle.net/6c42nugy/2/

Number of all elements in array:

数组中所有元素的数量:

var entireLength = a.length;

Percentage per type in comparison to whole

与整体相比,每种类型的百分比

var stringPerc = (stringCount)/(stringCount + entireLength)

var otherPerc = (entireLength - stringCount)/(stringCount + entireLength)

#3

Use a.join(';'); to convert the array into a string separated by semicolons.

使用a.join(';');将数组转换为由分号分隔的字符串。

To return the number of strings in the array, simply iterate through it and use toString.call() like this:

要返回数组中的字符串数,只需遍历它并使用toString.call(),如下所示:

var total = 0;
for (var i = 0, n = a.length; i < n; i++) {
    if (toString.call(a[i]) === '[object String]') total++;
}

To simply return the total number of items, you can do a.length.

要简单地返回项目总数,您可以执行a.length。

If you want the total value as in all the elements summed, you can do this:

如果你想要总和所有元素中的总值,你可以这样做:

var total = 0;
for (var i = 0, n = a.length; i < n; i++) {
    total += parseInt(a[i]);
}

If you want the average, just take the code above and do total / a.length;.

如果你想要平均值,只需取上面的代码并做total / a.length;。

#4

Here is my version:

这是我的版本:

var a = [1,2,3,4,5,"4","12","2",6,7,"4",3,"2"], sum = 0, strings = 0;

var joined = a.join(';');
console.log("Joined: " + joined);

for (var i = 0; i < a.length; i++) {
    sum += parseInt(a[i]);

    if (typeof a[i] === "string") {
        strings++;
    }
}

var avg = sum / a.length;

console.log('Sum: ' + sum);
console.log('Average: ' + avg);
console.log('Strings: ' + strings);

And link to JSFiddle.

并链接到JSFiddle。

#5

All results in one loop.

所有结果都在一个循环中。

0 ... n-4: Data
n-3: Count of all strings
n-2: Sum
n-1: Average

0 ... n-4:数据n-3:所有字符串的计数n-2:求和n-1:平均值

var data = [1, 2, 3, 4, 5, "4", "12", "2", 6, 7, "4", 3, "2"],
    result = data.concat(data.reduce(function (r, a, i) {
        typeof a === 'string' && r[0]++;
        r[1] += +a;
        r[2] = r[1] / i;
        return r;
    }, [0, 0, 0])).join(';');

document.write('<pre>' + JSON.stringify(result, 0, 4) + '</pre>');

#1