find all indexes of substring in string javascript

To find the index of string searchStr in the string str in JavaScript, call indexOf () method on this string str, and pass the other string searchStr as argument. After reading that answer, I switched to using double quotes, thanks for the hint. If either or both of the arguments are negative or NaN, the It is about searching for a string in an array, but this question is about searching for a string pattern, which can be achieved using string-search algorithms like Knuth-Morris-Pratt or Boyer-Moore. substr() methods, so you should be careful not to get What Is Behind The Puzzling Timing of the U.S. House Vacancy Election In Utah? Syntax string .indexOf ( searchvalue, start) Parameters Return Value The Differense Between String indexOf () and String search () The indexOf () method cannot search against a regular expression. Thanks for contributing an answer to Stack Overflow! Share. def find_substring (substring, string): """ Returns list of indices where substring begins in string >>> find_substring ('me', "The cat says . changes the string Brave New World to Brave New Web. Are modern compilers passing parameters in registers instead of on the stack? The indexOf () method of String values searches this string and returns the index of the first occurrence of the specified substring. substring S1 is found starting from ith character of S2 Write a java program to print the all possible substring of a given string without using substring method.. I had this problem as well, until I came up with this method. (Javascript), How to search for multiple sub-strings in a single query, indexOf, search up the string instead of down. This does not answer the question. The syntax to find the index of substring substr in string str is. If you need to replace Follow our guided path, With our online code editor, you can edit code and view the result in your browser, Join one of our online bootcamps and learn from experienced instructors, We have created a bunch of responsive website templates you can use - for free, Large collection of code snippets for HTML, CSS and JavaScript, Learn the basics of HTML in a fun and engaging video tutorial, Build fast and responsive sites using our free W3.CSS framework, Host your own website, and share it to the world with W3Schools Spaces. Approach: The idea is to use the concept of reversing the substrings of the given string. "; W3Schools is optimized for learning and training. What is the difficulty level of this exercise? This does not answers question & moreover, There are multiple providers for StringUtils. Similarly, the second if condition will evaluate to true although the string does not contain the word Samsung. The benchmark for such an approach is the Boyer-Moore algorithm. Also, don't mix single and double quotes unless you have good reason. OverflowAI: Where Community & AI Come Together, Search for all instances of a string inside a string, Behind the scenes with the folks building OverflowAI (Ep. OverflowAI: Where Community & AI Come Together, Get all occurrences of a substring in a very big string, Behind the scenes with the folks building OverflowAI (Ep. substring - source will give you the start index. JavaScript String indexOf() Explained By Practical Examples The 'substring ()' method lets us create substrings very easily. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. If a substring matches print its index. The lastIndexOf() method of String values searches this string and returns the index of the last occurrence of the specified substring. The same is the case with -1, which does not evaluate to false either. How do I keep a party together when they have conflicting goals? Find the starting indices of the substrings in string (S) which is made How to handle repondents mistakes in skip questions? How to Get Class Names of an HTML Element as List in JavaScript? The syntax of substring () is as follows: String.substring (startIndex, endIndex) startIndex: the index at which to start the extraction. What do multiple contact ratings on a relay represent? The British equivalent of "X objects in a trenchcoat". Why do we allow discontinuous conduction mode (DCM)? rev2023.7.27.43548. fetch(new Request("https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js", { method: 'HEAD', mode: 'no-cors' })).then(function(response) { How to Change Font Color of HTML Element in JavaScript? 594), Stack Overflow at WeAreDevelopers World Congress in Berlin, Temporary policy: Generative AI (e.g., ChatGPT) is banned, Preview of Search and Question-Asking Powered by GenAI, Search a string to find all the letters in JavaScript. The best answers are voted up and rise to the top, Not the answer you're looking for? How to Change Border Color of HTML Element in JavaScript? To check if a string contains a substring in JavaScript: The String.indexOf(searchValue[, fromIndex]) method takes two parameters: The String.indexOf() method returns the index of the first occurrence of searchValue in the string, or -1 if not found. But I want to get all the locations of where string is? Next: Write a JavaScript function to escape a HTML string. Delete an element from a Map in JavaScript, Get the first element of a Map in JavaScript, Get an element from a Map using JavaScript, Update an element in a Map using JavaScript. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. This is good for counting instances of a substring in a larger string, but does not return the indices of the matches. C++ Find Index of Substring in String - TutorialKart The JavaScript Tutorial website helps you learn JavaScript programming from scratch quickly and effectively. You can also subscribe to JavaScript: Count the occurrence of a substring in a string If string searchStr is not present in the string str, then indexOf() returns -1. Start with a Home JavaScript String Methods JavaScript String indexOf(). #1. Using a comma instead of and when you have a subject with two verbs. This is interesting in that it raises an ambiguity in the meaning of "all occurrences". How to return the frequency of a substring in a string? Which library is used is ambiguous. If there's .indexOf and ,lastIndexOf , shouldn't there be a function to get all index occurences? Depending on the number of parameters, we can use it in two ways. document.getElementById("carbon-block").appendChild(carbonScript); Can Henzie blitz cards exiled with Atsushi? indexOf() is an ECMAScript1 (ES1) feature. Enjoy our free tutorials like millions of other internet users since 1999, Explore our selection of references covering all popular coding languages, Create your own website with W3Schools Spaces - no setup required, Test your skills with different exercises, Test yourself with multiple choice questions, Create a free W3Schools Account to Improve Your Learning Experience, Track your learning progress at W3Schools and collect rewards, Become a PRO user and unlock powerful features (ad-free, hosting, videos,..), Not sure where you want to start? But in a given string it is possible to make a list of all the indexes of all the occurrences. Browse other questions tagged, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, The future of collective knowledge sharing, @Peter Thank you very much for you answer, it seem to be right, but this is, @Trufa: It always prints -1 at the end because, @ColinD that part I do get, what I don't understand is what is happen with the function for that to happen, it "loops" through the word looking for the occurrence of the character and until that is it can find no more right? To perform a case-insensitive search for the index of a substring within a string, you can convert both substring and string to lowercase before using the indexOf() method as follows: try { Why is an arrow pointing through a glass of water only flipped vertically but not horizontally? How to Change Border Style of Paragraph in JavaScript? Asking for help, clarification, or responding to other answers. But naming is hard and I might be wrong on this one. How to Change Border Width of Div in JavaScript? For this, we can use indexOf (which exists on String.prototype ): const index = location.indexOf('London'); // 15 console.log(index); Here we've used indexOf ('London') to search our String for a match! The String.prototype.indexOf() returns the index of the first occurrence of substring (substr) in a string (str): It returns -1 if the str does not contain the substr. Note that the string is very large, about 1MB in size, so I would need the fastest solution. The String.indexOf() method is case-sensitive, which means the following expressions evaluate to -1: If more than one matched substrings are present, String.indexOf() will return the first position of the first occurrence: The value 0, returned by the String.indexOf(), method does not evaluate to true. Examples might be simplified to improve reading and learning. Asking for help, clarification, or responding to other answers. substr()'s start index will wrap to the end of the string if it is negative, while substring() will clamp it to 0. How to Change the Border of Div in JavaScript? Thanks! How to find char in string and get all the indexes? BCD tables only load in the browser with JavaScript enabled. All browser compatibility updates at a glance, Frequently asked questions about MDN Plus. New! After finding the index of a substring, the search for the next one begins just after this index. Test your Programming skills with w3resource's quiz. How to Change Right Border of Paragraph in JavaScript? How to Change Font Weight of HTML Element in JavaScript? [Note: if guess can be longer than a single character, then it is possible, by analyzing the guess string, to loop through word faster than the above loops do. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. If start is greater than end, arguments are swapped: (4, 1) = (1, 4). Both "start" and "length" can be specified in the options. console.log(error); Here is an example: How common is it for US universities to ask a postdoc to bring their own laptop computer etc.. c - Get index of substring - Stack Overflow ES1 (JavaScript 1997) is fully supported in all browsers: If you want to report an error, or if you want to make a suggestion, do not hesitate to send us an e-mail: let text = "Hello world, welcome to the universe. How to Get Last Child of an HTML Element in JavaScript? How to Change Height of HTML Element in JavaScript? A short test is provided at the end. Create your own server using Python, PHP, React.js, Node.js, Java, C#, etc. Find index of last occurrence of a substring in a string, Where developers & technologists share private knowledge with coworkers, Reach developers & technologists worldwide, The future of collective knowledge sharing, How can 3 be a valid result? How to Change Width of Paragraph in JavaScript? How to get Attributes of HTML Element Element in JavaScript? Check if a string contains a substring using indexOf() in JavaScript What is a substring extractor? Any argument value that is NaN is treated as if it were 0. I'm wondering whether there is something like string.find_all () which can return all found indexes (not only the first from the beginning or the first from the end). How to Change Border Color of Paragraph in JavaScript? To learn more, see our tips on writing great answers. Creating strings Use our color picker to find different RGB, HEX and HSL colors, W3Schools Coding Game! How to Iterate over Children of HTML Element in JavaScript? Do the 2.5th and 97.5th percentile of the theoretical sampling distribution of a statistic always contain the true population parameter? Number of occurrences of a substring in a string [Javascript]. I am wondering if this is even possible without making any import method. Previous owner used an Excessive number of wall anchors. Site design / logo 2023 Stack Exchange Inc; user contributions licensed under CC BY-SA. Try it Syntax js Eliminative materialism eliminates itself - a familiar idea? There are subtle differences between the substring() and How to find all the indexes of all the occurrences of a substring in a Can a lightweight cyclist climb better than the heavier one by producing less power? Are the NEMA 10-30 to 14-30 adapters with the extra ground wire valid/legal to use and still adhere to code? is there a limit of speed cops can go on a high speed pursuit? Explanation: Input: S = "abcdefghij", A [] = {2, 5} Output: baedcjihgf Recommended: Please try your approach on {IDE} first, before moving on to the solution. Connect and share knowledge within a single location that is structured and easy to search. It will replace both Were all of the "good" terminators played by Arnold Schwarzenegger completely separate machines? This should print the list of positions without the -1 at the end that Peter Lawrey's solution has had. op's guess variable is a string. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. The substring () method does not change the original string. You could do it in a simple loop though: You can use indexOf('searchstring', ), using the index returned 'last time round' + 1 until you get -1 back. Connect and share knowledge within a single location that is structured and easy to search. } catch (error) { So if you leave the equal operator to explicitly verify the presence of the string, you might see incorrect results. Tutorials, references, and examples are constantly reviewed to avoid errors, but we cannot warrant full correctness of all content. The substring() method swaps its two arguments if int index = word.indexOf (guess); while (index >= 0) { System.out.println (index); index = word.indexOf (guess, index + 1); } It can also be done as a for loop: String.prototype.lastIndexOf() - JavaScript | MDN - MDN Web Docs How to Get First Child of an HTML Element in JavaScript? How to Change the Background Color of Div in JavaScript? The search () method accepts a regular expression and returns the index of the first match in a string: let index = str.search (regexp); Code language: JavaScript (javascript) In this syntax, the regexp is a regular expression. (with no additional restrictions). I would like to know how to get all the indexes of "n" ("guess") in the string "bannanas". How to draw a specific color with gpu shader, Story: AI-proof communication by playing music. and prints this last index of that is the not found (-1), is that what is happening? The substring() and slice() methods are This function returns a list of all the beginning indices of a substring in a string. The search () cannot take a start position argument. How to Get Height of an HTML Element in JavaScript? The starting index of the string is 1 . If the string to look for is not found, -1 is returned. How to Change Font Family of Div in JavaScript? The method returns the index of the last occurrence of the specified substring at a position less than or equal to position, which defaults to +Infinity. Mary needs to decode this string and pattern to form a large unique number so that she can put it up as an input to the defined algorithm to extract the secret message. JavaScript: String indexOf() method - TechOnTheNet By clicking Post Your Answer, you agree to our terms of service and acknowledge that you have read and understand our privacy policy and code of conduct. How to adjust the horizontal spacing of a table to get a good horizontal distribution? How to Change Font Color of Paragraph in JavaScript? How to Change Left Border of Div in JavaScript? Help the lynx collect pine cones, Join our newsletter and get access to exclusive content every month. Are arguments that Reason is circular themselves circular and/or self refuting? If you pass a non-RegExp into the method, it will convert . To perform a case-insensitive search for the index of a substring within a string, you can convert both substring and string to lowercase before using the indexOf () method as follows: let str = 'JS indexOf' ; let substr = 'js' ; let index = str.toLocaleLowerCase ().indexOf (substr.toLocaleLowerCase ()); console .log (index); // 0 (I don't know if that came out right). How to find all the matches of a Regular Expression in a String in Otherwise, it returns false. "Brave, Brave New World". To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Behind the scenes with the folks building OverflowAI (Ep. Does Python have a string 'contains' substring method? Python: Find an Index (or all) of a Substring in a String While this code may answer the question, providing additional context regarding how and/or why it solves the problem would improve the answer's long-term value.