JavaScript对象
1 indexOf（） 查找某个字符在字符串中第一次出现的位置，如果没有该字符，则返回-1
1 <!DOCTYPE html> 2 <html lang="en"> 3 <head> 4 <meta charset="UTF-8"> 5 <meta name="viewport" content="width=device-width, initial-scale=1.0"> 6 <title>Document</title> 7 </head> 8 <body> 9 <script> 10 var s1 = "abcdefg"; 11 //indexOf() 用于查找某个字符在字符串中的索引号，索引号从 0 开始 12 console.log(s1.indexOf("a")); 13 //如果该字符串中并不存在该字符，那么返回一个 -1 14 console.log(s1.indexOf("z")); 15 </script> 16 </body> 17 </html>
2.根据索引号返回字符串 charAt(index)
可以用来遍历字符串
<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <meta name="viewport" content="width=device-width, initial-scale=1.0"> <title>Document</title> </head> <body> <script> var s1 = "zhang"; //charAt(index) 根据索引号返回相应的字符 for(var i=0;i<s1.length;i++){ console.log(s1.charAt(i)); } </script> </body> </html>
3.截取字符串 substr(截取的起始位置，截取几个字符);
1 <!DOCTYPE html> 2 <html lang="en"> 3 4 <head> 5 <meta charset="UTF-8"> 6 <meta name="viewport" content="width=device-width, initial-scale=1.0"> 7 <title>Document</title> 8 </head> 9 10 <body> 11 <script> 12 var s1 = "zhangshan"; 13 //截取字符串 substr(截取的起始位置，截取几个字符); 14 console.log(s1.substr(2, 3)); 15 </script> 16 </body> 17 18 </html>
4,替换字符
replace（要被替换的字符，替换为的字符）； //只会替换第一字符
1 <!DOCTYPE html> 2 <html lang="en"> 3 4 <head> 5 <meta charset="UTF-8"> 6 <meta name="viewport" content="width=device-width, initial-scale=1.0"> 7 <title>Document</title> 8 </head> 9 10 <body> 11 <script> 12 //replac(被替换的字符，替换为的字符), 但是只能替换第一个字符 13 var s1 = "zhangshan"; 14 s1 = s1.replace("a","b"); 15 console.log(s1); 16 17 //replace()也可以替换字符串 18 var s2 = "abcefg" 19 s2 = s2.replace("abc","ujk"); 20 console.log(s2); 21 22 </script> 23 </body> 24 25 </html>
5. 将字符串转换成数组
split("分隔符")
1 <!DOCTYPE html> 2 <html lang="en"> 3 4 <head> 5 <meta charset="UTF-8"> 6 <meta name="viewport" content="width=device-width, initial-scale=1.0"> 7 <title>Document</title> 8 </head> 9 10 <body> 11 <script> 12 13 var s1 = "zhang,shan"; 14 s1 = s1.split(","); 15 console.log(s1); 16 </script> 17 </body> 18 19 </html>
