Regular expression small example - get number character and repeated the most

Get the most repeated characters and their number from a random string through regular expressions

 //First declare and define a random stringvar str = 'hgldsfkjhgkejhgkjg4654dfhghjf45gfgdrg4GJHGJK5dzfdf241b35sf';//1. Cut each character into an arrayvar arrStr = str.split('');//2. Sort character dataarrStr = arrStr.sort();//3. Assemble the sorted character data into a stringstr = arrStr.join('');var result = ''; //returns the most lettersvar count = 0; //counter//4. Capture group - the content matched by the expression in the regular expression, //Save to memory in a numbered or explicitly named group for later referencevar reg = /(\w)\1+/gi; //capturing group//Use replace to get the maximum number of charactersstr.replace(reg, function($0, $1) { //Collection: $0 represents a string of concatenated characters, $1 represents the first letter in a continuous stringif (count < $0.length) {result = $1;count = $0.length;}})console.log(" characters are: " + result + " , there are" + count + "");

The concept of capturing groups: Use regular expressions correctly to capture and non-capturing groups