mirror of https://github.com/noisymime/Arduino.git
124 lines
3.1 KiB
C++
124 lines
3.1 KiB
C++
/*
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Comparing Strings
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Examples of how to compare strings using the comparison operators
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created 27 July 2010
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modified 30 Aug 2011
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by Tom Igoe
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http://arduino.cc/en/Tutorial/StringComparisonOperators
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This example code is in the public domain.
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*/
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String stringOne, stringTwo;
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void setup() {
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Serial.begin(9600);
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stringOne = String("this");
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stringTwo = String("that");
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Serial.println("\n\nComparing Strings:");
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}
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void loop() {
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// two strings equal:
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if (stringOne == "this") {
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Serial.println("StringOne == \"this\"");
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}
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// two strings not equal:
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if (stringOne != stringTwo) {
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Serial.println(stringOne + " =! " + stringTwo);
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}
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// two strings not equal (case sensitivity matters):
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stringOne = "This";
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stringTwo = "this";
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if (stringOne != stringTwo) {
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Serial.println(stringOne + " =! " + stringTwo);
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}
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// you can also use equals() to see if two strings are the same:
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if (stringOne.equals(stringTwo)) {
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Serial.println(stringOne + " equals " + stringTwo);
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}
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else {
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Serial.println(stringOne + " does not equal " + stringTwo);
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}
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// or perhaps you want to ignore case:
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if (stringOne.equalsIgnoreCase(stringTwo)) {
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Serial.println(stringOne + " equals (ignoring case) " + stringTwo);
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}
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else {
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Serial.println(stringOne + " does not equal (ignoring case) " + stringTwo);
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}
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// a numeric string compared to the number it represents:
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stringOne = "1";
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int numberOne = 1;
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if (stringOne == numberOne) {
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Serial.println(stringOne + " = " + numberOne);
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}
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// two numeric strings compared:
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stringOne = "2";
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stringTwo = "1";
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if (stringOne >= stringTwo) {
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Serial.println(stringOne + " >= " + stringTwo);
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}
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// comparison operators can be used to compare strings for alphabetic sorting too:
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stringOne = String("Brown");
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if (stringOne < "Charles") {
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Serial.println(stringOne + " < Charles");
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}
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if (stringOne > "Adams") {
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Serial.println(stringOne + " > Adams");
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}
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if (stringOne <= "Browne") {
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Serial.println(stringOne + " <= Browne");
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}
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if (stringOne >= "Brow") {
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Serial.println(stringOne + " >= Brow");
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}
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// the compareTo() operator also allows you to compare strings
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// it evaluates on the first character that's different.
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// if the first character of the string you're comparing to
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// comes first in alphanumeric order, then compareTo() is greater than 0:
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stringOne = "Cucumber";
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stringTwo = "Cucuracha";
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if (stringOne.compareTo(stringTwo) < 0 ) {
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Serial.println(stringOne + " comes before " + stringTwo);
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}
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else {
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Serial.println(stringOne + " comes after " + stringTwo);
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}
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delay(10000); // because the next part is a loop:
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// compareTo() is handy when you've got strings with numbers in them too:
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while (true) {
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stringOne = "Sensor: ";
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stringTwo= "Sensor: ";
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stringOne += analogRead(A0);
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stringTwo += analogRead(A5);
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if (stringOne.compareTo(stringTwo) < 0 ) {
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Serial.println(stringOne + " comes before " + stringTwo);
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}
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else {
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Serial.println(stringOne + " comes after " + stringTwo);
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}
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}
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} |