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66 lines
2.5 KiB
C++
66 lines
2.5 KiB
C++
/*
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String indexOf() and lastIndexOf() functions
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Examples of how to evaluate, look for, and replace characters in a String
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created 27 Jul 2010
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modified 2 Apr 2012
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by Tom Igoe
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This example code is in the public domain.
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http://www.arduino.cc/en/Tutorial/StringIndexOf
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*/
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void setup() {
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// Open serial communications and wait for port to open:
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Serial.begin(9600);
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while (!Serial) {
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; // wait for serial port to connect. Needed for native USB port only
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}
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// send an intro:
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Serial.println("\n\nString indexOf() and lastIndexOf() functions:");
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Serial.println();
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}
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void loop() {
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// indexOf() returns the position (i.e. index) of a particular character in a
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// String. For example, if you were parsing HTML tags, you could use it:
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String stringOne = "<HTML><HEAD><BODY>";
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int firstClosingBracket = stringOne.indexOf('>');
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Serial.println("The index of > in the string " + stringOne + " is " + firstClosingBracket);
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stringOne = "<HTML><HEAD><BODY>";
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int secondOpeningBracket = firstClosingBracket + 1;
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int secondClosingBracket = stringOne.indexOf('>', secondOpeningBracket);
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Serial.println("The index of the second > in the string " + stringOne + " is " + secondClosingBracket);
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// you can also use indexOf() to search for Strings:
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stringOne = "<HTML><HEAD><BODY>";
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int bodyTag = stringOne.indexOf("<BODY>");
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Serial.println("The index of the body tag in the string " + stringOne + " is " + bodyTag);
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stringOne = "<UL><LI>item<LI>item<LI>item</UL>";
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int firstListItem = stringOne.indexOf("<LI>");
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int secondListItem = stringOne.indexOf("<LI>", firstListItem + 1);
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Serial.println("The index of the second list tag in the string " + stringOne + " is " + secondListItem);
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// lastIndexOf() gives you the last occurrence of a character or string:
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int lastOpeningBracket = stringOne.lastIndexOf('<');
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Serial.println("The index of the last < in the string " + stringOne + " is " + lastOpeningBracket);
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int lastListItem = stringOne.lastIndexOf("<LI>");
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Serial.println("The index of the last list tag in the string " + stringOne + " is " + lastListItem);
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// lastIndexOf() can also search for a string:
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stringOne = "<p>Lorem ipsum dolor sit amet</p><p>Ipsem</p><p>Quod</p>";
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int lastParagraph = stringOne.lastIndexOf("<p");
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int secondLastGraf = stringOne.lastIndexOf("<p", lastParagraph - 1);
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Serial.println("The index of the second to last paragraph tag " + stringOne + " is " + secondLastGraf);
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// do nothing while true:
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while (true);
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}
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