sizeof() — Maple v0.0.9 Documentation

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# `sizeof()`

The `sizeof` operator on the Maple returns the number of bytes needed to store a value of a given type[1]. This can be an ordinary numeric type, like `int`. It can be something more complicated, like a `struct` or `union`. If the argument to `sizeof` is an array, it returns the total number of bytes occupied by the array.

The general syntax looks like this:

    sizeof(type)
    sizeof(var)

## Example

The `sizeof` operator is useful for dealing with arrays (such as strings) where it is convenient to be able to change the size of the array without breaking other parts of the program.

This program prints out a text string one character at a time. Try changing the text phrase:

    char myStr[] = "this is a test";
    int i;

    void setup() {
      Serial.begin(9600);
    }

    void loop() {
      for (i = 0; i < sizeof(myStr) - 1; i++) {
        Serial.print(i, DEC);
        Serial.print(" = ");
        Serial.println(myStr[i], BYTE);
      }
    }

Note that `sizeof` returns the total number of bytes. So for larger variable types such as `int`, the for loop would look something like this:

    for (i = 0; i < (sizeof(myInts)/sizeof(int)) - 1; i++) {
      // do something with myInts[i]
    }

Footnotes

[1] | Technically (and pedantically) speaking, `sizeof` returns a multiple of the number of bits a `char` occupies in memory. However, on the Maple (this goes for most C++ implementations), a `char` occupies 8 bits = 1 byte. All the C++ standard guarantees, however, is that a `char` occupies at least 8 bits.

License and Attribution

This documentation page was adapted from the Arduino Reference Documentation, which is released under a Creative Commons Attribution-ShareAlike 3.0 License.

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