How Can I Count Character Occurrences and Validate Substring Lengths in JavaScript?

Find Character Occurrence Counts and String Validation in Strings

Question:

Determine the frequency of specific characters within a given string and ensure the length of individual substrings meets certain requirements.

Example:

Consider the following string:

var mainStr = "str1,str2,str3,str4"

Objective: Count the occurrences of the comma (,) character and individual strings (e.g., str1, str2, ...) in the string, with a maximum character limit of 15 for each substring.

Solution:

To count the occurrence of the comma character:

console.log(("str1,str2,str3,str4".match(/,/g) || []).length); //logs 3

To count the occurrence of individual strings:

console.log(("str1,str2,str3,str4".match(new RegExp("str", "g")) || []).length); //logs 4

For string validation, ensure each substring does not exceed 15 characters:

var strs = mainStr.split(",");
for (var i = 0; i < strs.length; i++) {
  if (strs[i].length > 15) {
    throw new Error("String exceeds maximum length");
  }
}

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