String.indexOf()
Description
Localise un caractère ou un String dans un autre objet String. Par défaut, recherche depuis le début de l'objet String, mais peut également débuter la recherche à partir d'un emplacement donné, permettant la localisation de toutes les instances du caractère ou du String à chercher.
Syntaxe
string.indexOf(valeur)
string.indexOf(valeur, debut)
Paramètres
- string: une variable de type String()
- valeur: la valeur à chercher (type char ou String)
- debut: l'emplacement du début de la recherche.
※ Remarque:
l'index du premier caractère est 0.
Valeurs Renvoyées
- Renvoie l'emplacement où valeur a été trouvé dans l'objet string, ou -1 si n'a pas été trouvé.
Exemple
void setup() {
Serial.begin(9600);
Serial.println("\n\nString indexOf() and lastIndexOf() functions:");
}
void loop() {
// indexOf() returns the position (i.e. index) of a particular character
// in a string. For example, if you were parsing HTML tags, you could use it:
String stringOne = "<HTML><HEAD><BODY>";
int firstClosingBracket = stringOne.indexOf('>');
Serial.println("The index of > in the string " + stringOne + " is " + firstClosingBracket);
stringOne = "<HTML><HEAD><BODY>";
int secondOpeningBracket = firstClosingBracket + 1;
int secondClosingBracket = stringOne.indexOf('>', secondOpeningBracket );
Serial.println("The index of the second > in the string " + stringOne + " is " + secondClosingBracket);
// you can also use indexOf() to search for Strings:
stringOne = "<HTML><HEAD><BODY>";
int bodyTag = stringOne.indexOf("<BODY>");
Serial.println("The index of the body tag in the string " + stringOne + " is " + bodyTag);
stringOne = "<UL><LI>item<LI>item<LI>item</UL>";
int firstListItem = stringOne.indexOf("<LI>");
int secondListItem = stringOne.indexOf("item", firstListItem + 1 );
Serial.println("The index of the second list item in the string " + stringOne + " is " + secondClosingBracket);
// lastIndexOf() gives you the last occurrence of a character or string:
int lastOpeningBracket = stringOne.lastIndexOf('<');
Serial.println("The index of the last < in the string " + stringOne + " is " + lastOpeningBracket);
int lastListItem = stringOne.lastIndexOf("<LI>");
Serial.println("The index of the last list item in the string " + stringOne + " is " + lastListItem);
// lastIndexOf() can also search for a string:
stringOne = "<p>Lorem ipsum dolor sit amet</p><p>Ipsem</p><p>Quod</p>";
int lastParagraph = stringOne.lastIndexOf("<p");
int secondLastGraf = stringOne.lastIndexOf("<p", lastParagraph - 1);
Serial.println("The index of the second last paragraph tag " + stringOne + " is " + secondLastGraf);
// do nothing while true:
while (true);
}
Voir Également
- Langage: Arduino - String
- Langage: String.charAt()
- Langage: String.compareTo()
- Langage: String.concat()
- Langage: String.endsWith()
- Langage: String.equals()
- Langage: String.equalsIgnoreCase()
- Langage: String.getBytes()
- Langage: String.lastIndexOf()
- Langage: String.length()
- Langage: String.replace()
- Langage: String.setCharAt()
- Langage: String.startsWith()
- Langage: String.substring()
- Langage: String.toCharArray()
- Langage: String.toLowerCase()
- Langage: String.toUpperCase()
- Langage: String.trim()
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