StringCharacters【arduino例子学习】

/*
  String charAt() and setCharAt()
 
 Examples of how to get and set characters of a String
 
 created 27 July 2010
 by Tom Igoe
 
 http://arduino.cc/en/Tutorial/StringCharacters
 
 This example code is in the public domain.
 */

void setup() {
  Serial.begin(9600);
  Serial.println("\n\nString  charAt() and setCharAt():");
}

void loop() {
  // make a string to report a sensor reading:
  String reportString = "SensorReading: 456";
  Serial.println(reportString);
  
  // the reading's most significant digit is at position 15 in the reportString:
  String mostSignificantDigit = reportString.charAt(15);
  Serial.println("Most significant digit of the sensor reading is: " + mostSignificantDigit);

// add blank space:
  Serial.println();
  
  // you can alo set the character of a string. Change the : to a = character
  reportString.setCharAt(13, '='); 
  Serial.println(reportString);

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

　　

/*
      String charAt(位置)   and   setCharAt(位置，目标字符)
         按位取字符                替换指定位的字符为目标字符
 Examples of how to get and set characters of a String
 

 created 27 July 2010
 by Tom Igoe
 
 http://arduino.cc/en/Tutorial/StringCharacters
 
 This example code is in the public domain.
 */

void setup() {
  Serial.begin(9600);
  Serial.println("\n\nString  charAt() and setCharAt():");
}

void loop() {
  // make a string to report a sensor reading:
  String reportString = "SensorReading: 456";
  Serial.println(reportString);
  
  // the reading's most significant digit is at position 15 in the reportString:
  String mostSignificantDigit = reportString.charAt(15);       /*  取reportString字符串数组 "SensorReading: 456" 的第15个字符，即reportString[15]=4  */
  Serial.println("Most significant digit of the sensor reading is: " + mostSignificantDigit);    /*  "+" 号表示组合字符的意思  */

// add blank space:
  Serial.println();
  
  // you can alo set the character of a string. Change the : to a = character
  reportString.setCharAt(13, '=');   /*  替换字符串数组的第13个字符为 "="  */

  Serial.println(reportString);

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

串口输出结果如下：

String  charAt() and setCharAt():
SensorReading: 456
Most significant digit of the sensor reading is: 4

SensorReading= 456