浅谈JavaScript数组简介

arr[arr.length] = 70;
arr[arr.length] = 80;
arr[arr.length] = 90;

var arr = [1,2,3,4,5];

var arr = new Array(1,2,3,4,5);

var arr = [10];

var arr = new Array(10);
console.log(arr);
console.log("arr.length="+arr.length);

var arr = ["孙悟空", 1, true, null, undefined];
console.log(arr);

var arr = [{name:"孙悟空"}, {name:"猪八戒"}, {name:"沙悟净"}];
console.log(arr[0].name);

var arr = [
    function () { alert(1) },
    function () { alert(2) }];

var arr = [[1,2,3],[4,5,6],[7,8,9]]; 
//3行3列的二维数组

  var a = new Array(
			new Array(10,20,30),
			new Array(11,22,33),
			new Array(45,56,67)
		)

var a = [
    ['a','b','c'],
    ['d','e','f'],
    ['g','h','i'],
    ['i','k','I']
]
var str = ''
for(var i=0;i<a.length;i++){
    for(var j=0;j<a[i].length;j++){
        str += a[i][j]+'\t';
    }
    str += '\n';
}
console.log("转置前:\n",str);
var res = []
for(var i=0;i<a[0].length;i++){
    res[i] = []
    for(var j=0;j<a.length;j++){
        res[i][j] = a[j][i];
    }
}
console.log("转置后：",res);

var str = ''
for(var i=0;i<a.length;i++){ //外循环:a.length表示二维数组的行数
    for(var j=0;j<a[i].length;j++){ //内循环：a[i].length表示i行的元素个数(列数)
        str += a[i][j]+'\t'
    }
    str += '\n'; //在每行的末尾添加换行符
}
console.log(str);
for(var i=0;i<a.length;i++){
    var max = a[i][0]
    for(var j=1;j<a[i].length;j++){
        if(max<a[i][j]){
            max = a[i][j];
        }
    }
    console.log("第"+(i+1)+"行的最大值是："+max)
}