上面给出的示例具有相同的输出，但是是的，方法不同，参数也不同。
该substring()方法的第二个参数是停止搜索的索引，而的第二个参数substr()是要返回的最大长度。
我们来看一个JavaScript中substr ()方法的示例-
<html>
<head>
<title>JavaScript String substr() Method</title>
</head>
<body>
<script>
var str = "Apples are round, and apples are juicy.";
document.write("(1,2): " + str.substr(1,2));
document.write("<br />(-2,2): " + str.substr(-2,2));
document.write("<br />(1): " + str.substr(1));
document.write("<br />(-20, 2): " + str.substr(-20,2));
document.write("<br />(20, 2): " + str.substr(20,2));
</script>
</body>
</html>我们来看一个JavaScript中substring()方法的示例-
<html>
<head>
<title>JavaScript String substring() Method</title>
</head>
<body>
<script>
var str = "Apples are round, and apples are juicy.";
document.write("(1,2): " + str.substring(1,2));
document.write("<br />(0,10): " + str.substring(0, 10));
document.write("<br />(5): " + str.substring(5));
</script>
</body>
</html>