| /* |
| String length() |
| |
| Examples of how to use length() in a String. |
| Open the Serial Monitor and start sending characters to see the results. |
| |
| created 1 Aug 2010 |
| by Tom Igoe |
| |
| http://arduino.cc/en/Tutorial/StringLengthTrim |
| |
| This example code is in the public domain. |
| */ |
| String txtMsg = ""; // a string for incoming text |
| int lastStringLength = txtMsg.length(); // previous length of the String |
| |
| 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("\n\nString length():"); |
| Serial.ptintln(); |
| } |
| |
| void loop() { |
| // add any incoming characters to the String: |
| while (Serial.available() > 0) { |
| char inChar = Serial.read(); |
| txtMsg += inChar; |
| } |
| |
| // print the message and a notice if it's changed: |
| if (txtMsg.length() != lastStringLength) { |
| Serial.println(txtMsg); |
| Serial.println(txtMsg.length()); |
| // if the String's longer than 140 characters, complain: |
| if (txtMsg.length() < 140) { |
| Serial.println("That's a perfectly acceptable text message"); |
| } |
| else { |
| Serial.println("That's too long for a text message."); |
| } |
| // note the length for next time through the loop: |
| lastStringLength = txtMsg.length(); |
| } |
| } |