java 代码

// Java中 获取指定字符串在另一个字符串中出现的次数        //方法一、//不区分大小写        String str = "Hello,my name is Ben.Please visit my website at http://www.forta.com/.";        String regex = "My";        Pattern pattern = Pattern.compile(regex,Pattern.CASE_INSENSITIVE);        int count = 0;        Matcher match = pattern.matcher(str);        while (match.find()) {            count++;        }        System.out.println(count);                //方法一、//区分大小写        String regex1 = "my";        Pattern pattern1 = Pattern.compile(regex1,Pattern.CASE_INSENSITIVE);//不区分大小写        int count1 = 0;        Matcher match1 = pattern1.matcher(str);        while (match1.find()) {            count1++;        }        System.out.println(count1);        //方法二、        String reg = "my";        int count2 = 0;        int index1 = 0;        //indexOf方法返回一个整数值，指出 String 对象内子字符串的开始位置。如果没有找到子字符串，则返回 -1        while ((index1 = str.indexOf(reg, index1)) != -1) {            index1 = index1 + reg.length();            count2++;        }        System.out.println(count2);222

 

替换不区分大小写

String input = "I like Java,jAva is very easy and jaVa is so popular.";          String replacement="ccc";          System.out.println(input);          System.out.println(input.replaceAll("java", replacement));          System.out.println(input.replaceAll("(?i)java", replacement)); I like Java,jAva is very easy and jaVa is so popular.I like Java,jAva is very easy and jaVa is so popular.I like ccc,ccc is very easy and ccc is so popular.

 

javascript 代码

ffunction myFunction(){  //方法一、 通过分割获取长度原理  var str = "Hello,my name is Ben.Please visit my website at http://www.forta.com/.";  var regex = "my";  var n = (str.split(regex)).length-1;  alert(n);       //方法二、通过正则实现  //eval(string) 函数可计算某个字符串，并执行其中的的 JavaScript 代码。  var reg=eval("/My/ig");//g代表全局查找，i代表不区分字母大小写  var count = str.match(reg).length;  alert(count); }都弹出 2