String Object Constructors
The String object allows you to manipulate strings of text in a variety of useful ways. You can append characters to Strings, combine Strings through concatenation, get the length of a String, search and replace substrings, and more. This tutorial shows you how to initialize String objects.
String stringOne = "Hello String"; // using a constant String String stringOne = String('a'); // converting a constant char into a String String stringTwo = String("This is a string"); // converting a constant string into a String object String stringOne = String(stringTwo + " with more"); // concatenating two strings String stringOne = String(13); // using a constant integer String stringOne = String(analogRead(0), DEC); // using an int and a base String stringOne = String(45, HEX); // using an int and a base (hexadecimal) String stringOne = String(255, BIN); // using an int and a base (binary) String stringOne = String(millis(), DEC); // using a long and a base String stringOne = String(5.698, 3); // using a float and the decimal places
All of these methods are valid ways to declare a String object. They all result in an object containing a string of characters that can be manipulated using any of the String methods. To see them in action, upload the code below onto an Arduino or Genuino board and open the Arduino IDE serial monitor. You'll see the results of each declaration. Compare what's printed by each println() to the declaration above it.
- Arduino or Genuino Board
There is no circuit for this example, though your board must be connected to your computer via USB and the serial monitor window of the Arduino Software (IDE) should be open.
String object – Your Reference for String objects
CharacterAnalysis - We use the operators that allow us to recognise the type of character we are dealing with.
StringAdditionOperator - Add strings together in a variety of ways.
StringAppendOperator - Use the += operator and the concat() method to append things to Strings
StringCaseChanges - Change the case of a string.
StringCharacters - Get/set the value of a specific character in a string.
StringComparisonOperators - Get/set the value of a specific character in a string.
StringIndexOf - Look for the first/last instance of a character in a string.
StringLength - Get the length of a string.
StringLengthTrim - Get and trim the length of a string.
StringReplace - Replace individual characters in a string.
StringStartsWithEndsWith - Check which characters/substrings a given string starts or ends with.
StringSubstring - Look for "phrases" within a given string.
StringToInt - Allows you to convert a String to an integer number.
Last revision 2015/08/11 by SM