Dada la string str de longitud N , la tarea es atravesar la string e imprimir todos los caracteres de la string dada.
Ilustración:
Input : “GeeksforGeeks” Output : G e e k s f o r G e e k s
Input. : “Coder” Output : C o d e r
Métodos:
- Usando un enfoque ingenuo
- Usando el método String.toCharArray()
- Usando CharacterIterator
- Usando StringTokenizer
- Usando el método String.split()
- Uso de la biblioteca de guayaba
- Usando el método String.chars()
- Uso de puntos de código
Método 1: enfoque ingenuo
El enfoque más simple para resolver este problema es iterar un ciclo sobre el rango [0, N – 1] , donde N denota la longitud de la string, usando la variable i e imprimir el valor de str[i] .
Ejemplo
Java
// Java Program to Iterate Over the Characters of a String
// Using Naive Approach
// Importing classes from respective packages
import java.io.*;
import java.util.*;
// Main class
class GFG {
// Method 1
// Function to traverse the string and
// print the characters of the string
static void traverseString(String str)
{
// Traverse the string
for (int i = 0; i < str.length(); i++) {
// Print current character
System.out.print(str.charAt(i) + " ");
}
}
// Method 2
// Main driver method
public static void main(String[] args)
{
// Custom input string
String str = "GeeksforGeeks";
// Calling the Method 1
traverseString(str);
}
}
Producción
G e e k s f o r G e e k s
Complejidad temporal: O(N)
Espacio auxiliar: O(1)
Método 2: Usar el método String.toCharArray()
En este enfoque, convertimos una string en una array de caracteres utilizando el método String.toCharArray() . Luego itere la array de caracteres usando for loop o for-each loop.
Ejemplo
Java
// Java Program to Iterate Over the Characters of a String
// Using String.toCharArray() method
// Importing classes from respective packages
import java.io.*;
import java.util.*;
// Main class
class GFG {
// Method 1
// To traverse the string and
// print the characters of the string
static void traverseString(String str)
{
char[] ch = str.toCharArray();
// Traverse the character array
for (int i = 0; i < ch.length; i++) {
// Print current character
System.out.print(ch[i] + " ");
}
}
// Method 2
// Main driver method
public static void main(String[] args)
{
// Custom input string
String str = "GeeksforGeeks";
// Calling the Method 1
traverseString(str);
}
}
Producción
G e e k s f o r G e e k s
Complejidad temporal: O(N)
Espacio auxiliar: O(N)
Método 3: Usar CharacterIterator
En este enfoque, usamos los métodos de CharacterIterator current() para obtener el carácter actual y next() para avanzar una posición. StringCharacterIterator proporciona la implementación de CharacterIterator.
Ejemplo
Java
// Java Program to Iterate Over the Characters of a String
// Using CharacterIterator
// Importing required libraries
import java.io.*;
import java.text.*;
// Main class
class GFG {
// Method 1
// To traverse the string and
// print the characters of the string
static void traverseString(String str)
{
CharacterIterator it
= new StringCharacterIterator(str);
// Iterate and print current character
while (it.current() != CharacterIterator.DONE) {
System.out.print(it.current() + " ");
// Moving onto next element in the object
// using next() method
it.next();
}
}
// Method 2
// Main driver method
public static void main(String[] args)
{
// Custom input string
String str = "GeeksforGeeks";
// Calling the Method 1
traverseString(str);
}
}
Producción
G e e k s f o r G e e k s
Complejidad temporal: O(N)
Espacio auxiliar: O(1)
Método 4: Usar StringTokenizer
En este enfoque, usamos la clase StringTokenizer en Java. Divide una string en tokens según el delimitador. Se desaconseja su uso.
StringTokenizer(String str, String delim, boolean flag): The first two parameters have same meaning. The flag serves following purpose. If the flag is false, delimiter characters serve to separate tokens. For example, if string is "hello geeks" and delimiter is " ", then tokens are "hello" and "geeks". If the flag is true, delimiter characters are considered to be tokens. For example, if string is "hello geeks" and delimiter is " ", then tokens are "hello", " " and "geeks".
Ejemplo
Java
// Java Program to Iterate Over the Characters of a String
// Using StringTokenizer
// Importing required libraries
import java.io.*;
import java.util.*;
// Main class
class GFG {
// Method 1
// To traverse the string and
// print the characters of the string
static void traverseString(String str)
{
// If returnDelims is true, use the string itself as
// a delimiter
StringTokenizer st
= new StringTokenizer(str, str, true);
while (st.hasMoreTokens()) {
System.out.print(st.nextToken() + " ");
}
System.out.println();
// If returnDelims is false, use an empty string as
// a delimiter
st = new StringTokenizer(str, "", false);
while (st.hasMoreTokens()) {
System.out.print(st.nextToken() + " ");
}
}
// Method 2
// Main driver method
public static void main(String[] args)
{
// Custom input string
String str = "GeeksforGeeks";
/// Calling the above Method1
traverseString(str);
}
}
Producción
G e e k s f o r G e e k s GeeksforGeeks
Complejidad temporal: O(N)
Espacio auxiliar: O(N)
Método 5: Usar el método String.split()
En este enfoque, usamos el método split() de la clase String. Divide la string en substrings en función de la expresión regular proporcionada.
Ejemplo
Java
// Java Program to Iterate Over the Characters of a String
// Using String.split() method
// Importing required classes from respective packages
import java.io.*;
import java.util.*;
// Main class
class GFG {
// Method 1
// To traverse the string and
// print the characters of the string
static void traverseString(String str)
{
// Split str around matches of empty string ""
String[] substrings = str.split("");
for (String ch : substrings) {
System.out.print(ch + " ");
}
}
// Method 2
// main driver method
public static void main(String[] args)
{
// Custom input string
String str = "GeeksforGeeks";
// Calling the Method1 to
// print the characters of the string
traverseString(str);
}
}
Producción
G e e k s f o r G e e k s
Complejidad temporal: O(N)
Espacio auxiliar: O(N)
Método 6: Uso de la biblioteca de guayaba
En este enfoque, usamos el método Lists.charactersOf(str) que devuelve una vista de una lista inmutable de caracteres.
Ejemplo
Java
// Java Program to Iterate Over the Characters of a String
// Using Guava Library
// Importing required classes from respective packages
import com.google.common.collect.Lists;
import java.io.*;
// Main class
class GFG {
// Method 1
// To traverse the string and
// print the characters of the string
static void traverseString(String str)
{
// Using enhanced for loop
for (Character ch : Lists.charactersOf(str)) {
System.out.print(ch + " ");
}
// A new line is required
System.out.println();
// Using listIterator on the List
// List<Characters>
// iterator()
// lambda
Lists.charactersOf(str)
.listIterator()
.forEachRemaining(
ch -> System.out.print(ch + " "));
// A new line is required
System.out.println();
// Using method reference with listIterator
// List<Characters>
// iterator()
Lists.charactersOf(str)
.listIterator()
.forEachRemaining(System.out::print);
}
// Method 2
// Main driver method
public static void main(String[] args)
{
// Custom input string
String str = "GeeksforGeeks";
// Calling the Method1 to
// print the characters of the string
traverseString(str);
}
}
Producción
G e e k s f o r G e e k s G e e k s f o r G e e k s GeeksforGeeks
Complejidad temporal: O(N)
Espacio auxiliar: O(N)
Método 7: Usar el método String.chars()
En este enfoque, usamos el método chars() de la clase String. Este método no devuelve el objeto Stream<Character> por motivos de rendimiento. Devuelve un objeto IntStream (flujo de enteros) que se puede convertir en Stream<Character>(flujo de caracteres).
Ejemplo
Java
// Java Program to Iterate Over the Characters of a String
// Using String.chars() method
// Importing classes from required packages
import com.google.common.collect.Lists;
import java.io.*;
// main class
class GFG {
// Method 1
// to traverse the string and
// print the characters of the string
static void traverseString(String str)
{
// Display message for better readability
System.out.println(
"Auto boxing into Stream<Character>");
// Using method reference
str.chars()
.mapToObj(Character::toChars)
.forEach(System.out::print);
str.chars().forEach(System.out::print);
// A new line is required
System.out.println();
// Using lambda expressions by casting int to char
str.chars()
.mapToObj(i -> Character.valueOf((char)i))
.forEach(System.out::print);
// A new line is required
System.out.println();
str.chars()
.mapToObj(i -> (char)i)
.forEach(System.out::print);
// A new line is required
System.out.println();
str.chars()
.mapToObj(
i -> new StringBuilder().appendCodePoint(i))
.forEach(System.out::print);
// A new line is required
System.out.println();
// Display message for better readability
System.out.println(
"Without boxing into Stream<Character>");
str.chars().forEach(
i -> System.out.print(Character.toChars(i)));
// A new line is required
System.out.println();
str.chars().forEach(i -> System.out.print((char)i));
// A new line is required for
// readability in output clearly
System.out.println();
str.chars().forEach(
i
-> System.out.print(
new StringBuilder().appendCodePoint(i)));
}
// Method 2
// main driver method
public static void main(String[] args)
{
// Custom input string
String str = "GeeksforGeeks";
// Calling the Method 1 to
// print the characters of the string
traverseString(str);
}
}
Producción
Auto boxing into Stream<Character> GeeksforGeeks7110110110711510211111471101101107115 GeeksforGeeks GeeksforGeeks GeeksforGeeks Without boxing into Stream<Character> GeeksforGeeks GeeksforGeeks GeeksforGeeks
Complejidad temporal: O(N)
Espacio auxiliar: O(N)
Método 8: Uso de puntos de código
En este enfoque, usamos el método String.codePoints() que devuelve un flujo de valores Unicode.
Ejemplo
Java
// Java Program to Iterate Over the Characters of a String
// Using Code Points
// importing classes from respective packages
import com.google.common.collect.Lists;
import java.io.*;
// main class
class GFG {
// Method 1
// To traverse the string and
// print the characters of the string
static void traverseString(String str)
{
// Display message for better readability
System.out.println(
"Auto boxing into Stream<Character>");
// Using method reference
str.codePoints()
.mapToObj(Character::toChars)
.forEach(System.out::print);
str.codePoints().forEach(System.out::print);
// New line is required
System.out.println();
// Using lambda expressions by casting int to char
str.codePoints()
.mapToObj(i -> Character.valueOf((char)i))
.forEach(System.out::print);
// New line is required
System.out.println();
// now using the codepoints() over the string
str.codePoints()
.mapToObj(i -> (char)i)
.forEach(System.out::print);
// New line is required
System.out.println();
str.codePoints()
.mapToObj(
i -> new StringBuilder().appendCodePoint(i))
.forEach(System.out::print);
System.out.println();
// Display message for readability in output
System.out.println(
"Without boxing into Stream<Character>");
str.codePoints().forEach(
i -> System.out.print(Character.toChars(i)));
System.out.println();
str.codePoints().forEach(
i -> System.out.print((char)i));
System.out.println();
str.codePoints().forEach(
i
-> System.out.print(
new StringBuilder().appendCodePoint(i)));
}
// Method 2
// main driver method
public static void main(String[] args)
{
// Custom input string
String str = "GeeksforGeeks";
// Calling the Method1 to
// print the characters of the string
traverseString(str);
}
}
Producción
Auto boxing into Stream<Character> GeeksforGeeks7110110110711510211111471101101107115 GeeksforGeeks GeeksforGeeks GeeksforGeeks Without boxing into Stream<Character> GeeksforGeeks GeeksforGeeks GeeksforGeeks
Complejidad temporal: O(N)
Espacio auxiliar: O(N)
Publicación traducida automáticamente
Artículo escrito por Ganeshchowdharysadanala y traducido por Barcelona Geeks. The original can be accessed here. Licence: CCBY-SA