Energia

Examples > Strings

### String Appending Operators

This example shows how to append strings together with different techniques.

### Hardware Required

- MSP-EXP430G2 LaunchPad

### Relevant Groundwork

Just as you can concatenate Strings with other data objects using the StringAdditionOperator, you can also use the +=operator and the cconcat() method to append things to Strings. The += operator and the concat() method work the same way, it's just a matter of which style you prefer. The two examples below illustrate both, and result in the same String:

      String stringOne = "A long integer: ";

      // using += to add a long variable to a string:
      stringOne += 123456789;

or

      String stringOne = "A long integer: ";

      // using concat() to add a long variable to a string:
      stringTwo.concat(123456789);

In both cases, stringOne equals "A long integer: 123456789". Like the + operator, these operators are handy for assembling longer strings from a combination of data objects.

### Circuit

Only LaunchPad is required for this example.

image developed using Fritzing. For more circuit examples, see the Fritzing project page.

### Schematic

### Code Explanation

In the program , we first declare two strings. We then demonstrate various append examples.

### Code

    /*
      Appending to Strings using the += operator and concat()

     Examples of how to append different data types to strings

     created 27 July 2010
     modified 2 Apr 2012
     by Tom Igoe

     This example code is in the public domain.
     */
    String stringOne, stringTwo;

    void setup() {
      // Open serial communications and wait for port to open:
      Serial.begin(9600);

      stringOne = String("Sensor ");
      stringTwo = String("value");
      // send an intro:
      Serial.println("\n\nAppending to a string:");
      Serial.println();
    }

    void loop() {
      Serial.println(stringOne);  // prints  "Sensor "

      // adding a string to a string:
      stringOne += stringTwo;
      Serial.println(stringOne);  // prints "Sensor value"

      // adding a constant string to a string:
      stringOne += " for input ";
      Serial.println(stringOne);  // prints "Sensor value for input"

      // adding a constant character to a string:
      stringOne += 'A';
      Serial.println(stringOne);   // prints "Sensor value for input A"

      // adding a constant integer to a string:
      stringOne += 0;
      Serial.println(stringOne);   // prints "Sensor value for input A0"

      // adding a constant string to a string:
      stringOne += ": ";
      Serial.println(stringOne);  // prints "Sensor value for input"

      // adding a variable integer to a string:
      stringOne += analogRead(A0);
      Serial.println(stringOne);   // prints "Sensor value for input A0: 456" or whatever analogRead(A0) is

      Serial.println("\n\nchanging the Strings' values");
      stringOne = "A long integer: ";
      stringTwo = "The millis(): ";

      // adding a constant long integer to a string:
      stringOne += 123456789;
      Serial.println(stringOne);   // prints "A long integer: 123456789"

      // using concat() to add a long variable to a string:
      stringTwo.concat(millis());
      Serial.println(stringTwo); // prints "The millis(): 43534" or whatever the value of the millis() is

      // do nothing while true:
      while(true);
    }

### Working Video

(Insert Video Here)

### Try it out:

- Append multiple strings together and print to serial

See Also

- setup()
- loop()
- println()

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

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