js统计数组中的元素个数

统计数组["Array","Baca","AcdaC"]中所有的A的个数。


var js_List=["Array","Baca","AcdaC"];  

var count=0;  

document.write("在以下字符中：<br/>");  

for(var i in js_List){  

document.write(js_List[i]+"<br/>");  

if(js_List[i].indexOf("a")!=-1||js_List[i].indexOf("A")!=-1)  

count++;  


<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
<script type="text/javascript">
window.onload=function(){
    var shuzu=["Array","Baca","AcdaC"];
    var count=0;
    for(var i=0;i<shuzu.length;i++){
        for(var j=0;j<shuzu[i].length;j++){
            if('A'==shuzu[i][j]){
                count=count+1;
            }
        }
    }
    alert(count);
}
</script>
</head>
<body>

</body>
</html>

function fn(strs, str) {
return strs.length - strs.replace(new RegExp(str, "g"), "").length
};
fn("AAAAAAAAAAAAAAAAAAAaa", "a");

    const test = ["Array", "Baca", "AcdaC"];
    let res = 0;
    test.map((cur) => {
      //遍历数组，每个字符串正则匹配A的个数加到结果上去
      res += cur.match(/A/g) ? cur.match(/A/g).length : 0;
    });
    console.log(res);//2

["Array","Baca","AcdaC"].join("").match(/A/g).length