数组值计数javascript [英] Array value count javascript

问题描述

如何根据值计算数组..
我有一个具有此值的数组..

How can I count the array depending on the value.. I have an array with this value..

var myArr = new Array(3);
myArr[0] = "a";
myArr[1] = "a";
myArr[2] = "b";

我需要根据值计算数组

数值A的数组是2
数值B的数组是1

Array with Value A is 2 Array with value B is 1

谢谢！

推荐答案

var myArr = new Array(3);
myArr[0] = "a";
myArr[1] = "a";
myArr[2] = "b";


function count(array, value) {
  var counter = 0;
  for(var i=0;i<array.length;i++) {
    if (array[i] === value) counter++;
  }
  return counter;
}

var result = count(myArr, "a");
alert(result);

如果您对内置功能感兴趣...您可以随时添加自己的功能。

If you're interested in a built-in function... you could always add your own.

Array.prototype.count = function(value) {
  var counter = 0;
  for(var i=0;i<this.length;i++) {
    if (this[i] === value) counter++;
  }
  return counter;
};

然后你可以像这样使用它。

Then you could use it like this.

var result = myArr.count("a");
alert(result);

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