How do I implement the following (Python pseudocode) in C++? if argv[1].startswith(‘–foo=’): foo_value = int(argv[1][len(‘–foo=’):]) (For example, if argv[1] is –foo=98, then foo_value is 98.) Update: I’m hesitant to look into Boost, since I’m just looking at making a very small change to a simple little command-line tool (I’d rather not have to learn how … Read more
For example, assuming that x = filename.jpg, I want to get filename, where filename could be any file name (Let’s assume the file name only contains [a-zA-Z0-9-_] to simplify.). I saw x.substring(0, x.indexOf(‘.jpg’)) on DZone Snippets, but wouldn’t x.substring(0, x.length-4) perform better? Because, length is a property and doesn’t do character checking whereas indexOf() is … Read more
I’ve been updating some of my old code and answers with Swift 3 but when I got to Swift Strings and Indexing with substrings things got confusing. Specifically I was trying the following: let str = “Hello, playground” let prefixRange = str.startIndex..<str.startIndex.advancedBy(5) let prefix = str.substringWithRange(prefixRange) where the second line was giving me the following … Read more
Given that strings are immutable in .NET, I’m wondering why they have been designed such that string.Substring() takes O(substring.Length) time, instead of O(1)? i.e. what were the tradeoffs, if any? 5 Answers 5 UPDATE: I liked this question so much, I just blogged it. See Strings, immutability and persistence The short answer is: O(n) is … Read more
Let’s say I have a string ‘gfgfdAAA1234ZZZuijjk’ and I want to extract just the ‘1234’ part. I only know what will be the few characters directly before AAA, and after ZZZ the part I am interested in 1234. With sed it is possible to do something like this with a string: echo “$STRING” | sed … Read more
This question already has answers here: How to check if a String contains another String in a case insensitive manner in Java? (19 answers) Closed 8 years ago. I have two Strings, str1 and str2. How do I check if str2 is contained within str1, ignoring case? 6 s 6
In Objective-C the code to check for a substring in an NSString is: NSString *string = @”hello Swift”; NSRange textRange =[string rangeOfString:@”Swift”]; if(textRange.location != NSNotFound) { NSLog(@”exists”); } But how do I do this in Swift? 28 s 28 You can do exactly the same call with Swift: Swift 4 & Swift 5 In Swift … Read more
I have a variable of type std::string. I want to check if it contains a certain std::string. How would I do that? Is there a function that returns true if the string is found, and false if it isn’t? 15 s 15 Use std::string::find as follows: if (s1.find(s2) != std::string::npos) { std::cout << “found!” << … Read more
Given a filename in the form someletters_12345_moreleters.ext, I want to extract the 5 digits and put them into a variable. So to emphasize the point, I have a filename with x number of characters then a five digit sequence surrounded by a single underscore on either side then another set of x number of characters. … Read more
What is the difference between alert(“abc”.substr(0,2)); and alert(“abc”.substring(0,2)); They both seem to output “ab”. 1Best Answer 11 The difference is in the second argument. The second argument to substring is the index to stop at (but not include), but the second argument to substr is the maximum length to return. Links? https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/substr https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/substring
