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c435f05 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 | /*
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
This example code is in the public domain.
https://www.arduino.cc/en/Tutorial/BuiltInExamples/StringLengthTrim
*/
String txtMsg = ""; // a string for incoming text
unsigned 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 native USB port only
}
// send an intro:
Serial.println("\n\nString length():");
Serial.println();
}
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();
}
}
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