Web程序设计基础 JavaScript编程训练：数组_第1关:数组的创建、读写和长度

第1关：数组的创建、读写和长度

var array1 = [1,2,3,"js",4,true,"hello"];
var array2 = [true,true,"java",2.1];
function mainJs(a) {
	//请在此处编写代码
    a = parseInt(a);
    /*********begin*********/
    b = array1.length;
    c = array2.length;
    if (a == b) return (array1[b-1]);
    else return (array2[c-1]);
 
    /*********end*********/
}

第2关：数组元素的增减

var testArray = [12,"java","js","c","c++",24,36,"python","c#","css"];
function mainJs(a, b) {
    a = parseInt(a);
    b = parseInt(b);
    //请在此处编写代码
    /*********begin*********/
    for (i = 0; i < a; i++){
        c = testArray.pop();
        testArray.unshift(c)
    }
    return (testArray[b]);
 
 
    /*********end*********/
}

第3关：数组的常用方法

function mainJs(myArray) {
    myArray = myArray.split(",");
    //请在此处编写代码
    /*********begin*********/
    var x = new Array();
    var y = new Array();
    var l = myArray.length;
    var i = 0;
    while (i < l) {
        i = myArray.indexOf("a", i);
        if (i ==-1) break;
        x.push(i);
        i++;
    }
    i = 0;
    while (i < l) {
        i = myArray.indexOf("b", i);
        if (i ==-1) break;
        y.push(i);
        i++;
    }
    return (x.concat(y));
 
    /*********end*********/
}