JavaScript基础学习 数组

数组

    js开始学习
    
        //
        var arr1 = [1, 2, 'zhangsan', true];
        console.log(arr1);
        console.log(arr1[2]);

        //遍历数组
        var arr = ['red', 'green', 'blue', 'pink'];
        for (var i = 0; i  arr2[i + 1]) {
                max = arr2[i];
            }
        }
        console.log('数组当中最大值为:' + max);

        // 数组转换为字符串
        var arr3 = ['red', 'green', 'blue', 'pink'];
        var sep = '';
        for (var i = 0; i < arr3.length; i++) {
            sep += arr3[i] + '|';
        }
        console.log(sep);

        console.log('-------------------------------------');
        //1.新数组元素  修改length长度
        var arr4 = ['red', 'green', 'blue'];
        console.log(arr4.length);
        arr4.length = 5;
        console.log(arr4);
        console.log(arr4[3]);
        console.log(arr4[4]);

        //2.新增数组元素 修改索引号  追加数组元素
        var arr5 = ['red', 'green', 'blue'];
        arr5[3] = 'pink';
        console.log(arr5);
        arr5[0] = 'yellow';
        console.log(arr5[0]);
        arr5 = '不要这样赋值'; //不要直接给数组名赋值，否则里面的数组元素都没有了
        console.log(arr5);
    

翻转数组案例

    js开始学习
    
 
        var arr5 = ['red', 'green', 'blue', 'pink', 'purple', 'yellow', 'organe'];
        var temp = '';
        for (var i = 0; i < (arr5.length - 1) / 2; i++) {
            temp = arr5[i];
            arr5[i] = arr5[arr5.length - i - 1];
            arr5[arr5.length - i - 1] = temp;
        }
        console.log(arr5);