数组值计数javascript

Question

如何根据值计算数组..我有一个具有此值的数组..

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

我需要根据值来计算数组

值A的数组是2数组,值B是1

谢谢!

Answer 1

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.

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.

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