2 common methods for JS to simply judge the number of times a character appears in another string

This article describes two common methods for JS to simply judge the number of times a character appears in another string. Share it for your reference, as follows:

After search verification, two methods are provided.

1. Principle of obtaining length through segmentation

var s = '';
var n = (('.')).length-1;
alert(n); //Popt 2

2. Implement through regular

function patch(re,s){
  re=eval("/"+re+"/ig")
  return (re).length;
}
var s = 'tools.';
alert(patch('t',s)); //Popt 2

PS: Regarding regular operations, here are two very convenient regular expression online tools for your reference:

JavaScript regular expression online testing tool:
http://tools./regex/javascript

Regular expression online generation tool:
http://tools./regex/create_reg

In addition, we recommend two simple and easy-to-use online character statistics tools for your reference:

Online word count tool:
http://tools./code/zishutongji

Online character statistics and editing tools:
http://tools./code/char_tongji

For more information about JavaScript, readers who are interested in reading this site's special topic:JavaScript regular expression skills》、《Summary of JavaScript replacement operation skills》、《Summary of JavaScript search algorithm skills》、《Summary of JavaScript data structure and algorithm techniques》、《JavaScript traversal algorithm and skills summary》、《Summary of json operation skills in JavaScript》、《Summary of JavaScript Errors and Debugging Skills"and"Summary of JavaScript mathematical operations usage》

I hope this article will be helpful to everyone's JavaScript programming.