作业--2019-05-07

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>0507作业</title>
</head>
<body>
<script>
// 1. 使用forEach()遍历数组
// 2. 通过查手册编写splice()方法的案例，实现数组元素的添加，删除和更新操作

document.write('创建数组');
var books = ['Html','css','JavaScript','PHP','MYSQL'];
books.forEach(function (value,key) {
document.write(key + '--' +value +'');
});
document.write('');
//document.write(books + " ")

document.write('删除第3个元素');
books.splice(2,1);
books.forEach(function (value,key) {
document.write(key + '--' +value +'');
});

document.write('');
document.write('插入java到第2个元素位置,');
books.splice(1,0,"java")

books.forEach(function (value,key) {
document.write(key + '--' +value +'');
});

document.write('');
document.write('将第五个mysql改为sql,');
books.splice(4,1,"SQL")
books.forEach(function (value,key) {
document.write(key + '--' +value +'');
});

</script>

</body>
</html>

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