<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>截取</title>
</head>
<body>
<script>
var str = '我愛(ài)我的祖國(guó),我的祖國(guó)是中國(guó)';
var str2 = str.substring(3,7);
console.log("從第三個(gè)截取到第7個(gè),不包含第7個(gè)",str2);
var str3 = str.substr(3,7);
console.log("從第3個(gè)截取7個(gè)",str3);
// 如果只填一個(gè)參數(shù)substr 和substring 一樣
var str4 = str.substring(3);
console.log("從第3個(gè)截取到最后",str4);
</script>
</body>
</html>
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>截取</title>
</head>
<body>
<script>
var str=BIDUPSID=79C7474D75B8166AB5923127E8E2CA6B; PSTM=1576652895; BAIDUID=79C7474D75B8166A0997826FD1853E9E:FG=1; BD_UPN=12314753; BDORZ=FFFB88E999055A3F8A630C64834BD6D0; delPer=0; BD_HOME=0; H_PS_PSSID=1456_21083_30210_30284_26350;
// 求出BAIDUID 的值;
// 思路 查找BAIDUID= 的位置 =p1
// 查找p1 后的分號(hào);
// 截取p1到分號(hào)的字符
var p1 = str.indexOf("BAIDUID=");
var p2 = str.indexOf(";",p1);
var val = str.substring(p1+8,p2);
console.log(str);
console.log("BAIDUID的值是",val);
</script>
</body>
</html>
