Working with strings in swift

String Manipulation in Swift Language

Hello there !!! Welcome to my post about string manipulation in swift.The current post covers the latest swift 4 syntax as specified in the apple developer site. This post will show you all the necessary operations that we need to do at sometime while programming in swift. I hope you will find this post informative and useful. Happy coding :)

String Declaration:

	let constantString = "This is a single line string"
	//now a multiline string
	let quotation = """
	The White Rabbit put on his spectacles. "Where shall I begin,
	please your Majesty?" he asked.
	"Begin at the beginning," the King said gravely, "and go on
	till you come to the end; then stop."
	"""

view raw StringsManipulationDemo.swift hosted with ❤ by GitHub

String Concatenation:

	var firstString = "Hello Everyone."
	var secondString = "This is Nikesh's Blog"
	var newString = firstString + secondString
	print(newString)
	//OUTPUT: Hello Everyone.This is Nikesh's Blog

view raw StringConcatenation.swift hosted with ❤ by GitHub

Working with characters and substrings:

	var someString = "Hello there"
	//Create a string using array of characters
	let charArray: [Character] = ["N","I","K","E", "S", "H"]
	let srtingFromArray = String(charArray) // "NIKESH"
	//Get array of characters from a string
	var charatctesFromString = Array(someString) // ["H", "e", "l", "l", "o", " ", "t", "h", "e", "r", "e"]
	print(charatctesFromString)
	//characters count in string
	var numberOfCharacters = someString.count
	//print all the characters in a string
	for char in someString{
	print(char)
	}
	//H
	//e
	//l
	//l
	//o
	//
	//t
	//h
	//e
	//r
	//e
	//Access characters at different index
	var firstCharacter = someString.first
	var lastCharacter = someString.last
	//get character at nth index
	func getCharAt(index: Int, string: String) -> Character {
	let index = string.index (string.startIndex, offsetBy: index)
	return string[index]
	}
	var char1 = getCharAt(index: 6, string: "Apple Inc") // I
	//get substring bty specifying and start and end indices
	func substring(string: String, fromIndex: Int, toIndex: Int) -> String? {
	if fromIndex < toIndex && toIndex < string.count /*use string.characters.count for swift3*/{
	let startIndex = string.index(string.startIndex, offsetBy: fromIndex)
	let endIndex = string.index(string.startIndex, offsetBy: toIndex)
	return String(string[startIndex..<endIndex])
	}else{
	return nil
	}
	}
	substring(string: "Hello World", fromIndex: 0, toIndex: 3)! // Hel
	substring(string: "Hello World", fromIndex: 0, toIndex: 20) // nil

view raw StringsCharactersDemo.swift hosted with ❤ by GitHub

Strings Comparison:

	let quotation = "Hello World"
	var sameQuotation = "Hello World"
	if quotation == sameQuotation {
	print("These two strings are considered equal")
	}
	// Prints "These two strings are considered equal"

view raw StringsComparison.swift hosted with ❤ by GitHub

Case Conversion in strings

	var str = "hello Nikesh"
	//Capitalize first letter of every word
	var capitalizedStr = str.capitalized // "Hello Nikesh"
	//Change string to uppercase
	str.uppercased() // "HELLO NIKESH"
	//change string to lowercase
	str.lowercased() // "hello nikesh"

view raw CaseConversionSnippet.swift hosted with ❤ by GitHub