Introduction to Scala String Scala string is an immutable object that means the object cannot be modified. Each element of a string is associated with an index number. The first character is associated with the number 0, the second with the number 1, etc. Class java.lang.The string contains different predefined functions that are very useful to perform various operations on strings. var I = “intellipaat” Some methods are – length – Returns the number of Unicode code units in a string e.g. println(I.length) Output 11 charAt – It has an index number as an argument and returns the Char at the specified index. e.g. println(I.charAt(2)) Output t startsWith – Tests whether this string starts with the argument of this method. e.g. println(A.startsWith("I")) Output True endsWith – Tests whether this string ends with the argument of this method. e.g. println(I.endsWith("i")) Output False indexOf – Returns the index within this string object of the first occurrence of the string argument. e.g. println(I.indexOf("n")) Output 1 substring – Returns a new string that is a substring of this string. It may take one or two arguments. If it takes one argument then substring begins with the specified index to the end of the string and if it takes two arguments then first specify the starting of string and second string specify the ending of the string e.g. println(I.substring(1,4)) Output nte concat – This method appends its argument to this string e.g. I = I.concat("Hello"); println(A) Output intellipaathello contains – Examine whether a string contains a particular substring or not. e.g. if(I.contains("inte")) println("contains specified string") Output contains specified string replace – It takes two arguments from which the first argument is replaced by the second argument form the specified string. e.g. println(I.replace('a','t')) println(I) Output intellipttt toLowerCase – converts all of the characters in this string to lower case. e.g. println(I.toLowerCase()) Output intellipaat toUpperCase – converts all of the characters in this string to upper case. e.g. println(I.toUpperCase()) Output INTELLIPAAT trim – Returns a copy of the string with leading and trailing whitespace omitted. isEmpty – Returns true if method length returns 0. codePointAt – Returns the Unicode code point at the specified index. toCharArray – Transforms a string into an array