Arduino - StringConstructor

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String

## String()

#### Description

Constructs an instance of the String class. There are multiple versions that construct Strings from different data types (i.e. format them as sequences of characters), including:

- a constant string of characters, in double quotes (i.e. a char array)
- a single constant character, in single quotes
- another instance of the String object
- a constant integer or long integer
- a constant integer or long integer, using a specified base
- an integer or long integer variable
- an integer or long integer variable, using a specified base
- a float or double, using a specified decimal palces

Constructing a String from a number results in a string that contains the ASCII representation of that number. The default is base ten, so

String thisString = String(13);
[Get Code]

gives you the String "13". You can use other bases, however. For example,

String thisString = String(13, HEX);
[Get Code]

gives you the String "D", which is the hexadecimal representation of the decimal value 13. Or if you prefer binary,

String thisString = String(13, BIN);
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gives you the String "1101", which is the binary representation of 13.

#### Syntax

String(val)
String(val, base)
String(val, decimalPlaces)

#### Parameters

val: a variable to format as a String - string, char, byte, int, long, unsigned int, unsigned long, float, double
base (optional) - the base in which to format an integral value
decimalPlaces (only if val is float or double) - the desired decimal places

#### Returns

an instance of the String class

### Examples

All of the following are valid declarations for Strings.

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
[Get Code]

#### See also

- String Constructor Tutorial

Reference Home

Corrections, suggestions, and new documentation should be posted to the Forum.

The text of the Arduino reference is licensed under a Creative Commons Attribution-ShareAlike 3.0 License. Code samples in the reference are released into the public domain.

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