We are required to write a JavaScript function that takes in two strings, say str1 and str2. The function should then count and return the number of times str2 appears in str1'
For example −
count('this is a string', 'is') should return 2;
Example
The code for this will be −
const str1 = 'this is a string'; const str2 = 'is'; const countOccurrences = (str1, str2, allowOverlapping = true) => { str1 += ""; str2 += ""; if (str2.length <= 0) return (str1.length + 1); var n = 0, pos = 0, step = allowOverlapping ? 1 : str2.length; while (true) { pos = str1.indexOf(str2, pos); if (pos >= 0) { ++n; pos += step; } else break; } return n; }; console.log(countOccurrences(str1, str2));
Output
And the output in the console will be −
2