Reference for Wiring version 0024+. If you have a previous version, use the reference included with your software. If you see any errors or have any comments, let us know.
Class | String |
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Name | charAt() |
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Examples | String s1 = String("string number one"); // declares s1 with an initial string void setup() { Serial.begin(9600); pinMode(48, OUTPUT); // turn ON wiring hardware LED digitalWrite(48, HIGH); String s2 = String(10000); // s2 holds "10000" Serial.println("s2 holds: " + s2); String s3 = String(567000, DEC); // s3 holds "567000" Serial.println("s3 holds: " + s3); String s4 = "string number four"; // s4 holds "string number four" Serial.println("s4 holds: " + s4); s4 += " plus another part"; // use + operator to add a string Serial.println("now s4 holds: " + s4); // user + operator when printing to serial char c = s4.charAt(5); // get character at position 5 Serial.print("c holds: "); Serial.println(c); // prints 'g' String s5 = String("string number one"); // s5 holds "string number one" int cmp = s1.compareTo(s5); // compare s1 to s5 if(cmp == 0) { Serial.println("s1 and s5 are equal"); // prints equal } else { Serial.println("s1 and s5 are different"); } if(s5.endsWith("one")) // check if s5 ends with "one" Serial.println("s5 ends with "one""); // prints "s5 ends with "one"" if(s1.equals(s5)) // check if s1 equal to s5 Serial.println("s1 and s5 are equal"); // prints equal String s6 = String("string NUMBER one"); // s6 holds "string NUMBER one" if(s5.equalsIgnoreCase(s6)) // check if s5 and s6 are equal ignoring case differences Serial.println("s6 and s5 are equal ignoring the case"); // prints equal Serial.print("index of char R pn s6 is: "); Serial.println(s6.indexOf('R'), DEC); // prints 12 Serial.print("index of char R on s6 from index 13 is: "); Serial.println(s6.indexOf('R', 13), DEC); // prints -1, not found String s7 = s6.substring(7, 13); Serial.println("s7 is: "+s7); // prints "NUMBER" Serial.print("index of string "NUMBER" on s6 is: "); Serial.println(s6.indexOf(s7), DEC); // prints 7 Serial.print("last index of char 'n' on s6 is: "); Serial.println(s6.lastIndexOf('n'), DEC); // prints 15 Serial.print("length of s6 is: "); Serial.println(s6.length(), DEC); // prints 15 s6.setCharAt(15, 'N'); // set character at index 15 to 'N' Serial.println("s6 is: "+s6); // prints "string NUMBER oNe" if(s6.startsWith("string")) // check if s6 starts with "string" Serial.println("s6 starts with "string""); // s6 starts with "string" string Serial.println("s6 to lower case is: "+s6.toLowerCase()); // prints "string number one" Serial.println("s6 to upper case is: "+s6.toUpperCase()); // prints "STRING NUMBER ONE" s6.concat(" plus spaces at the end "); // concat a string Serial.println("s6 is: "+s6); // prints "string NUMBER oNe plus spaces at the end " Serial.println("trim of s6 is: "+s6.trim()); // prints "string NUMBER oNe plus spaces at the end" Serial.println("s6 is: "+s6.replace('e', '5')); // prints "string NUMBER oN5 plus spac5s at th5 5nd" const char *str = s6.toCharArray(); // get the char array Serial.print("str is: "); Serial.println(str); // prints "string NUMBER oNe plus spaces at the end " const byte *bytes = s6.getBytes(); // get the byte array } void loop() { } |
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Description | Returns the character at the specified index. An index ranges from 0 to the length of the string minus 1. The first character of the sequence is at index 0, the next at index 1, etc. | ||
Syntax | charAt(index) |
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Parameters |
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Returns | char | ||
Usage | Application |