diff --git a/String/CountSubstrings.js b/String/CountSubstrings.js new file mode 100644 index 0000000000..f936f8eab0 --- /dev/null +++ b/String/CountSubstrings.js @@ -0,0 +1,29 @@ +/** + * @function countSubstrings + * @description Given a string of words or phrases, count the occurrences of a substring + * @param {String} str - The input string + * @param {String} substring - The substring + * @return {Number} - The number of substring occurrences + * @example countSubstrings("This is a string", "is") => 2 + * @example countSubstrings("Hello", "e") => 1 + */ + +const countSubstrings = (str, substring) => { + if (typeof str !== 'string' || typeof substring !== 'string') { + throw new TypeError('Argument should be string') + } + + if (substring.length === 0) return str.length + 1 + + let count = 0 + let position = str.indexOf(substring) + + while (position > -1) { + count++ + position = str.indexOf(substring, position + 1) + } + + return count +} + +export { countSubstrings } diff --git a/String/test/CountSubstrings.test.js b/String/test/CountSubstrings.test.js new file mode 100644 index 0000000000..66628b1a14 --- /dev/null +++ b/String/test/CountSubstrings.test.js @@ -0,0 +1,52 @@ +import { countSubstrings } from '../CountSubstrings' + +describe('CountSubstrings', () => { + it('count multiple occurrences of substring in a string', () => { + const str = 'This is a string' + const substring = 'is' + const count = countSubstrings(str, substring) + expect(count).toBe(2) + }) + + it('should return 0 when input substring has no occurrences', () => { + const str = 'Jurassic Park' + const substring = 'World' + const count = countSubstrings(str, substring) + expect(count).toBe(0) + }) + + it('should return 1 when input substring is of length 1 that is equal to string', () => { + const str = 's' + const substring = 's' + const count = countSubstrings(str, substring) + expect(count).toBe(1) + }) + + it('should return the correct result when input string contains spaces', () => { + const str = 'ab cd ef ghi' + const substring = ' ' + const count = countSubstrings(str, substring) + expect(count).toBe(4) + }) + + it('should return the correct result when input substring contains number or special characters', () => { + const str = 'abc1@2def1@2' + const substring = '1@2' + const count = countSubstrings(str, substring) + expect(count).toBe(2) + }) + + it('should return string.length + 1 when the input substring is an empty string', () => { + const str = 'empty' + const substring = '' + const count = countSubstrings(str, substring) + expect(count).toBe(6) + }) + + it('should return correct result when input is overlapping substring', () => { + const str = 'aaa' + const substring = 'aa' + const count = countSubstrings(str, substring) + expect(count).toBe(2) + }) +})
Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.
Alternative Proxies: