数组
<!DOCTYPE html>
<html>
<head>
<title>js开始学习</title>
<script>
//
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 <= 2; i++) {
console.log(arr[i]);
}
var arr2 = [87, 645, 23, 33, 90, 100];
var max = 0;
for (var i = 0; i < arr2.length; i++) {
if (arr2[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);
</script>
</head>
<body>
</body>
</html>
翻转数组案例
<!DOCTYPE html>
<html>
<head>
<title>js开始学习</title>
<script>
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);
</script>
</head>
<body>
</body>
</html>