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learing:examples:stringcharacters

String Character Analysis

In this example we use the operators that allow us to recognise the type of character we are dealing with. It is useful to check if a character is ASCII, or is upper case, or numeric, or it is a punctuation mark and so forth. The options available cover a variety of situations and this is demonstrated in the sketch below. Every character sent to the board through the serial monitor of the Arduino Software (IDE) is analysed by the sketch that returns all the information it was able to find. A single character may trigger more than one condition and therefore you may get multiple answers for a single entry.

The available operators are:

isAlphaNumeric() it's alphanumeric isAlpha() it's alphabetic isAscii() it's ASCII isWhitespace() it's whitespace isControl() it's a control character isDigit() it's a numeric digit isGraph() it's a printable character that's not whitespace isLowerCase() it's lower case isPrintable() it's printable isPunct() it's punctuation isSpace() it's a space character isUpperCase() it's upper case isHexadecimalDigit() it's a valid hexadecimaldigit (i.e. 0 - 9, a - F, or A - F)

Hardware Required

Arduino or Genuino Board Circuit

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.

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

Code

Open the serial monitor window of the Arduino Software (IDE) and type in a single character at a time, then press Send to get a report about that specific character.

/*
  Character analysis operators
 
 Examples using the character analysis operators.
 Send any byte and the sketch will tell you about it.
 
 created 29 Nov 2010
 modified 2 Apr 2012
 by Tom Igoe
 
 This example code is in the public domain.
 */
 
void setup() {
  // Open serial communications and wait for port to open:
  Serial.begin(9600);
  while (!Serial) {
    ; // wait for serial port to connect. Needed for Leonardo only
  }
 
  // send an intro:
  Serial.println("send any byte and I'll tell you everything I can about it");
  Serial.println();
}
 
void loop() {
  // get any incoming bytes:
  if (Serial.available() > 0) {
    int thisChar = Serial.read();
 
    // say what was sent:
    Serial.print("You sent me: \'");
    Serial.write(thisChar);
    Serial.print("\'  ASCII Value: ");
    Serial.println(thisChar);
 
    // analyze what was sent:
    if (isAlphaNumeric(thisChar)) {
      Serial.println("it's alphanumeric");
    }
    if (isAlpha(thisChar)) {
      Serial.println("it's alphabetic");
    }
    if (isAscii(thisChar)) {
      Serial.println("it's ASCII");
    }
    if (isWhitespace(thisChar)) {
      Serial.println("it's whitespace");
    }
    if (isControl(thisChar)) {
      Serial.println("it's a control character");
    }
    if (isDigit(thisChar)) {
      Serial.println("it's a numeric digit");
    }
    if (isGraph(thisChar)) {
      Serial.println("it's a printable character that's not whitespace");
    }
    if (isLowerCase(thisChar)) {
      Serial.println("it's lower case");
    }
    if (isPrintable(thisChar)) {
      Serial.println("it's printable");
    }
    if (isPunct(thisChar)) {
      Serial.println("it's punctuation");
    }
    if (isSpace(thisChar)) {
      Serial.println("it's a space character");
    }
    if (isUpperCase(thisChar)) {
      Serial.println("it's upper case");
    }
    if (isHexadecimalDigit(thisChar)) {
      Serial.println("it's a valid hexadecimaldigit (i.e. 0 - 9, a - F, or A - F)");
    }
 
    // add some space and ask for another byte:
    Serial.println();
    Serial.println("Give me another byte:");
    Serial.println();
  }
}
learing/examples/stringcharacters.txt · 最后更改: 2017/04/07 10:03 (外部编辑)