1.7 KiB
1.7 KiB
id | title | challengeType | forumTopicId | dashedName |
---|---|---|---|---|
596fda99c69f779975a1b67d | Count occurrences of a substring | 5 | 302237 | count-occurrences-of-a-substring |
--description--
Create a function, or show a built-in function, to count the number of non-overlapping occurrences of a substring inside a string.
The function should take two arguments:
- the first argument being the string to search, and
- the second a substring to be searched for.
It should return an integer count.
The matching should yield the highest number of non-overlapping matches.
In general, this essentially means matching from left-to-right or right-to-left.
--hints--
countSubstring
should be a function.
assert(typeof countSubstring === 'function');
countSubstring("the three truths", "th")
should return 3
.
assert.equal(countSubstring(testCases[0], searchString[0]), results[0]);
countSubstring("ababababab", "abab")
should return 2
.
assert.equal(countSubstring(testCases[1], searchString[1]), results[1]);
countSubstring("abaabba*bbaba*bbab", "a*b")
should return 2
.
assert.equal(countSubstring(testCases[2], searchString[2]), results[2]);
--seed--
--after-user-code--
const testCases = ['the three truths', 'ababababab', 'abaabba*bbaba*bbab'];
const searchString = ['th', 'abab', 'a*b'];
const results = [3, 2, 2];
--seed-contents--
function countSubstring(str, subStr) {
return true;
}
--solutions--
function countSubstring(str, subStr) {
const escapedSubStr = subStr.replace(/[.+*?^$[\]{}()|/]/g, '\\$&');
const matches = str.match(new RegExp(escapedSubStr, 'g'));
return matches ? matches.length : 0;
}