Scala - String Methods

There are many methods to work on strings and we will discuss here a few important ones.

int length() - Get string length:

var str1:String = "one"
println("Length is " + str1.length());

String concat(String) - Concat one string to another:

var str1:String = "one"
var str2:String = str1.concat(" two")
println("Combined string is " + str2);

char charAt(int index) - Returns the character at the given index first index being 0:

var str:String = "New York"
println("Char at 5th index is " + str.charAt(4));

String replace(char oldChar, char newChar) - Returns a new string after replacing all occurrences of string oldChar with string newChar:

var str:String = "New York"
println("New string is " + str.replace("York","Shire"));

String replaceAll(char oldChar, char newChar) - Returns a new string after replacing all occurrences of string oldChar with string newChar. It is same as replace function but additionally, it can also use regular expressions (regex).

var str:String = "New York 1ab2c3"
println("New string is " + str.replaceAll("[0-9]","x"));

To replace multiple chars, use | separator between patterns.

var str:String = "New York"
// replace all w and k with z
println("New string is " + str.replaceAll("w|k","z"));

String[] split(String regex) - Splits the string around matches of the given regular expression.

var str:String = "New,York,Hello, There"
var strarray = new Array[String](3)
strarray = str.split(",")
println("New string is " + strarray(0));
println(strarray.deep.mkString("\n"))

String substring(int beginIndex, int endIndex) - Returns the substring of a string ending at endIndex-1.

var str:String = "NewxYorkyHello, There"
var str1 = str.substring(4,9)
println("New string is " + str1)