计算字符串中的重复字母 [英] Count repeated letters in a string

问题描述

我遇到了以下问题：
我需要在字符串中找到重复的字符。
基本上我想要的是正则表达式，它将匹配如此

I'm stuck with the following problem: I need to find repeated characters in a string. Basically what I want is regular expression that will match like that

hello - ["ll"];
here  - ["ee"];
happiness   -  ["pp","ss"];
pupil  -  ["pp"];

我有一个匹配连续重复字符的那个

I have the one that matches consecutive repeated characters

  /([a-z])\1+/g

还会匹配重复的字符和它们之间的所有内容，例如这个

Also the one that will match repeated chars and everything between them like this one

   /([a-z])(?:.*)\1+/g

但是找不到正确的。

推荐答案

您可以使用

([a-zA-Z]).*(\1)

演示正则表达式

既然您已经澄清了您正在寻找一种解决方案，它将处理字符串中除双字母以外的其他内容，您应该使用非正则表达式方法，例如：

Since you have clarified that you are looking for a solution that will handle something other than double letters in a string, you should use a non-regex approach such as:

使用字符串中的字符数构建关联数组：

Build an associative array with the count of the characters in the string:

var obj={}
var repeats=[];
str='banana'

for(x = 0, length = str.length; x < length; x++) {
    var l = str.charAt(x)
    obj[l] = (isNaN(obj[l]) ? 1 : obj[l] + 1);
}

console.log(obj)

打印

{ b: 1, a: 3, n: 2 }

然后构建一个规范数组：

Then build an array of your specifications:

for (var key in obj) {
    if (obj.hasOwnProperty(key) && obj[key]>1) {
        repeats.push(new Array( obj[key]+ 1 ).join( key ));
    }
}
console.log(repeats)

打印：

[ 'aaa', 'nn' ]

这篇关于计算字符串中的重复字母的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！