character – Page 10 – Tarik Billa

Max length UITextField

November 30, 2022 by Tarik

With Swift 5 and iOS 12, try the following implementation of textField(_:shouldChangeCharactersIn:replacementString:) method that is part of the UITextFieldDelegate protocol: func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool { guard let textFieldText = textField.text, let rangeOfTextToReplace = Range(range, in: textFieldText) else { return false } let substringToReplace = textFieldText[rangeOfTextToReplace] let count … Read more

Get nth character of a string in Swift

November 24, 2022 by Tarik

Attention: Please see Leo Dabus’ answer for a proper implementation for Swift 4 and Swift 5. Swift 4 or later The Substring type was introduced in Swift 4 to make substrings faster and more efficient by sharing storage with the original string, so that’s what the subscript functions should return. Try it out here extension … Read more

How can I use modulo operator (%) in JavaScript? [duplicate]

November 21, 2022 by Tarik

It’s the remainder operator and is used to get the remainder after integer division. Lots of languages have it. For example: 10 % 3 // = 1 ; because 3 * 3 gets you 9, and 10 – 9 is 1. Apparently it is not the same as the modulo operator entirely.

How to index characters in a Golang string?

November 20, 2022 by Tarik

Interpreted string literals are character sequences between double quotes “” using the (possibly multi-byte) UTF-8 encoding of individual characters. In UTF-8, ASCII characters are single-byte corresponding to the first 128 Unicode characters. Strings behave like slices of bytes. A rune is an integer value identifying a Unicode code point. Therefore, package main import “fmt” func … Read more

Remove all special characters from a string in R?

November 15, 2022 by Tarik

You need to use regular expressions to identify the unwanted characters. For the most easily readable code, you want the str_replace_all from the stringr package, though gsub from base R works just as well. The exact regular expression depends upon what you are trying to do. You could just remove those specific characters that you … Read more

How to check if character is a letter in Javascript?

November 15, 2022 by Tarik

I don’t believe there is a built-in function for that. But it’s easy enough to write with a regex function isLetter(str) { return str.length === 1 && str.match(/[a-z]/i); }

Why is the alphabet split into multiple ranges in this C code?

November 15, 2022 by Tarik

The author of this code presumably had to support EBCDIC at some point, where the numeric values of the letters are non-contiguous (gaps exist between I, J and R, S, as you may have guessed). It is worth noting that the C and C++ standards only guarantee that the characters 0 to 9 have contiguous … Read more

How to get the number of characters in a string

October 23, 2022 by Tarik

You can try RuneCountInString from the utf8 package. returns the number of runes in p that, as illustrated in this script: the length of “World” might be 6 (when written in Chinese: “世界”), but the rune count of “世界” is 2: package main import “fmt” import “unicode/utf8” func main() { fmt.Println(“Hello, 世界”, len(“世界”), utf8.RuneCountInString(“世界”)) } … Read more

Convert data.frame column format from character to factor

October 21, 2022 by Tarik

Hi welcome to the world of R. mtcars #look at this built in data set str(mtcars) #allows you to see the classes of the variables (all numeric) #one approach it to index with the $ sign and the as.factor function mtcars$am <- as.factor(mtcars$am) #another approach mtcars[, ‘cyl’] <- as.factor(mtcars[, ‘cyl’]) str(mtcars) # now look at … Read more

What method in the String class returns only the first N characters?

October 13, 2022 by Tarik

public static string TruncateLongString(this string str, int maxLength) { if (string.IsNullOrEmpty(str)) return str; return str.Substring(0, Math.Min(str.Length, maxLength)); } In C# 8 or later it is also possible to use a Range to make this a bit terser: public static string TruncateLongString(this string str, int maxLength) { return str?[0..Math.Min(str.Length, maxLength)]; } Which can be further reduced … Read more