JS-小技巧-国家城市联动

var arr=new array(4);
arr[0]=["china",‘beijing‘,‘chengdu‘,‘wuhan‘];
arr[1]=["america",‘newyork‘,‘houston‘,‘atlanta‘];
arr[2]=["germany",‘xx‘,‘yy‘,‘zz‘];
arr[3]=["japan",‘tokyo‘,‘ban‘,‘heidao‘];

<select id="country" onchange="add1(this.value);">

function add1(val){
    
    var cityId=document.getElementById("city");
    var options1=cityId.getElementsByTagName("option");
    for(var m=0;m<options1.legnth;m++){

        var op=options1[m];
        cityId.removeChild(op);
        m--;

    }

    for(int i=0;i<arr.length;i++){

        arr1=arr[i];
        if(arr1[0]==val){

            for(int j=1;j<arr1.length;j++){

                var value1=arr1[i];
                var option1=document.createElement("option");
                var text1=document.createTextNode(value1);
                option1.appendChild(text1);
                cityId.appendChild(option1);

            }

        }

    }

}