Files
JavaScript/String/PatternMatching.js
Ephraim Atta-Duncan e112434dee Add tests to Math (#423)
* Add prettier config

* test: add test to check for absolute function

* chore: es5 to es6

* test: add test to check mean function

* test: add test for sum of digit

* test: add test for factorial

* test: add test for fibonnaci

* test: add test for find HCF

* test: add test for lcm

* test: add gridget test

* test: add test for mean square error

* test: add test for modular binary exponentiation

* test: add tests for palindrome

* test: add test for pascals triangle

* test: add tests for polynomial

* test: add tests for prime check

* test: add tests for reverse polish notation

* test: add tests for sieve of eratosthenes

* test: add tests for pi estimation monte carlo method

* chore: move tests to test folder

* chore: fix standardjs errors
2020-10-12 01:17:49 +05:30

34 lines
1.2 KiB
JavaScript

/*
Pattern matching is case insensitive as
the inputs are converted to lower case before the
algorithm is run.
The algorithm will run through the entire text and
return the starting index if the given pattern is
available in the text
*/
const checkIfPatternExists = (text, pattern) => {
if (typeof text !== 'string' || typeof pattern !== 'string') {
throw new TypeError('Given input is not a string')
}
const textLength = text.length // Store the length of the text in a variable
const patternLength = pattern.length // Store the length of the pattern in a variable
// Iterate through the text until the textlength - patternlength index
for (let i = 0; i <= textLength - patternLength; i++) {
// For each character in the text check if the subsequent character
// are matching the given pattern; if not break from the condition
for (let j = 0; j < textLength; j++) {
if (text[i + j] !== pattern[j]) break
// For each iteration of j check if the value of
// j + 1 is equal to the length of the pattern
if (j + 1 === patternLength) {
return `Given pattern is found at index ${i}`
}
}
}
}
export { checkIfPatternExists }