如何计算字符串中的字符串出现？ [英] How to count string occurrence in string?

问题描述

如何计算特定字符串在另一个字符串中出现的次数。例如，这就是我在Javascript中尝试做的事情：

How can I count the number of times a particular string occurs in another string. For example, this is what I am trying to do in Javascript:

var temp = "This is a string.";
alert(temp.count("is")); //should output '2'

推荐答案

<$ c正则表达式中的$ c> g （ global 的缩写）表示搜索整个字符串而不是仅查找第一个匹配项。这匹配是两次：

The g in the regular expression (short for global) says to search the whole string rather than just find the first occurrence. This matches is twice:

var temp = "This is a string.";
var count = (temp.match(/is/g) || []).length;
console.log(count);

并且，如果没有匹配项，则返回 0 ：

And, if there are no matches, it returns 0:

var temp = "Hello World!";
var count = (temp.match(/is/g) || []).length;
console.log(count);

这篇关于如何计算字符串中的字符串出现？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！