En este artículo, discutiremos las formas de comparar una variable con valores.
Método 1: La idea es comparar cada variable individualmente con todos los valores múltiples a la vez.
Programa 1:
C++
// C++ program to compare one variable
// with multiple variable
#include <iostream>
using namespace std;
// Driver Code
int main()
{
// Variable to be compared
char character = 'a';
// Compare the given variable
// with vowel using || operator
// Check for vowel
if (character == ('a' || 'e'
|| 'i' || 'o'
|| 'u')) {
cout << "Vowel";
}
// Otherwise Consonant
else {
cout << "Consonant";
}
return 0;
}
Java
// Java program to compare one variable
// with multiple variable
import java.util.*;
class GFG
{
// Driver Code
public static void main(String[] args)
{
// Variable to be compared
char character = 'a';
// Compare the given variable
// with vowel using || operator
// Check for vowel
if (character == ('a' || 'e'
|| 'i' || 'o'
|| 'u')) {
System.out.print("Vowel");
}
// Otherwise Consonant
else {
System.out.print("Consonant");
}
}
}
// This code is contributed by Rajput-Ji
Python3
# Python program to compare one variable
# with multiple variable
# Driver Code
if __name__ == '__main__':
# Variable to be compared
character = 'a';
# Compare the given variable
# with vowel using or operator
# Check for vowel
if (character == ('a' or 'e' or 'i' or 'o' or 'u')):
print("Vowel");
# Otherwise Consonant
else:
print("Consonant");
# This code contributed by shikhasingrajput
C#
// C# program to compare one variable
// with multiple variable
using System;
class GFG
{
// Driver Code
public static void Main(String[] args)
{
// Variable to be compared
char character = 'a';
// Compare the given variable
// with vowel using || operator
// Check for vowel
if (character == ('a' || 'e'
|| 'i' || 'o'
|| 'u')) {
Console.Write("Vowel");
}
// Otherwise Consonant
else {
Console.Write("Consonant");
}
}
}
// This code is contributed by 29AjayKumar
Javascript
<script>
// Javascript program to compare one variable
// with multiple variable
// Variable to be compared
var character = 'a';
// Compare the given variable
// with vowel using || operator
// Check for vowel
if (character == ('a'. charCodeAt(0) ||
'e'. charCodeAt(0) ||
'i'. charCodeAt(0) ||
'o'. charCodeAt(0) ||
'u'. charCodeAt(0)))
{
document.write("Vowel");
}
// Otherwise Consonant
else
{
document.write("Consonant");
}
// This code is contributed by SoumikMondal
</script>
Producción
Consonant
Explicación:
el código anterior da una respuesta incorrecta o un error, ya que comparar la variable de la manera anterior es incorrecto y obliga a codificar de la siguiente manera:
C++
// C++ program to compare one variable
// with multiple variable
#include <iostream>
using namespace std;
// Driver Code
int main()
{
// Variable to be compared
char character = 'a';
// Compare the given variable
// with vowel individually
// Check for vowel
if (character == 'a'
|| character == 'e'
|| character == 'i'
|| character == 'o'
|| character == 'u') {
cout << "Vowel";
}
// Otherwise Consonant
else {
cout << "Consonant";
}
return 0;
}
Java
// Java program to compare
// one variable with multiple
// variable
import java.util.*;
class GFG{
// Driver Code
public static void main(String[] args)
{
// Variable to be compared
char character = 'a';
// Compare the given variable
// with vowel using || operator
// Check for vowel
if (character == 'a' || character == 'e' ||
character == 'i' || character == 'o' ||
character == 'u')
{
System.out.print("Vowel");
}
// Otherwise Consonant
else
{
System.out.print("Consonant");
}
}
}
// This code is contributed by 29AjayKumar
Python3
# Python3 program to compare
# one variable with multiple
# variable
# Driver Code
if __name__ == '__main__':
# Variable to be compared
character = 'a';
# Compare the given variable
# with vowel using or operator
# Check for vowel
if (character == 'a' or
character == 'e' or
character == 'i' or
character == 'o' or
character == 'u'):
print("Vowel");
# Otherwise Consonant
else:
print("Consonant");
# This code contributed by Princi Singh
C#
// C# program to compare
// one variable with multiple
// variable
using System;
class GFG{
// Driver Code
public static void Main(String[] args)
{
// Variable to be compared
char character = 'a';
// Compare the given variable
// with vowel using || operator
// Check for vowel
if (character == 'a' || character == 'e' ||
character == 'i' || character == 'o' ||
character == 'u')
{
Console.Write("Vowel");
}
// Otherwise Consonant
else
{
Console.Write("Consonant");
}
}
}
// This code is contributed by gauravrajput1
Javascript
<script>
// javascript program to compare one variable
// with multiple variable
// Driver Code
function checkCharacter(character)
{
// Compare the given variable
// with vowel using || operator
// Check for vowel
if (character == 'a' || character == 'e' ||
character == 'i' || character == 'o' ||
character == 'u') {
document.write("Vowel");
}
// Otherwise Consonant
else {
document.write("Consonant");
}
}
// Driver Code
checkCharacter('a');
// This code is contributed by bunnyram19.
</script>
Producción
Vowel
Método 2: uso de máscara de bits: otro enfoque es verificar entre múltiples grupos de valores y luego crear una máscara de bits de los valores y luego verificar que se establezca ese bit.
Programa 2:
C++
// C++ program to compare a value
// with multiple values
#include <iostream>
using namespace std;
// Driver Code
int main()
{
// Create bitmasks
unsigned group_1 = (1 << 1) | (1 << 2) | (1 << 3);
unsigned group_2 = (1 << 4) | (1 << 5) | (1 << 6);
unsigned group_3 = (1 << 7) | (1 << 8) | (1 << 9);
// Values to be checked
int value_to_check = 9;
// Checking with created bitmask
if ((1 << value_to_check)
& group_1) {
cout << "found a match in group 1";
}
if ((1 << value_to_check)
& group_2) {
cout << "found a match in group 2";
}
if ((1 << value_to_check)
& group_3) {
cout << "found a match in group 3";
}
return 0;
}
Java
// Java program to compare a value
// with multiple values
import java.util.*;
class GFG{
// Driver Code
public static void main(String[] args)
{
// Create bitmasks
int group_1 = (1 << 1) |
(1 << 2) | (1 << 3);
int group_2 = (1 << 4) |
(1 << 5) | (1 << 6);
int group_3 = (1 << 7) |
(1 << 8) | (1 << 9);
// Values to be checked
int value_to_check = 9;
// Checking with created bitmask
if (((1 << value_to_check) &
group_1) > 0)
{
System.out.print("found a match " +
"in group 1");
}
if (((1 << value_to_check) &
group_2) > 0)
{
System.out.print("found a match " +
"in group 2");
}
if (((1 << value_to_check) &
group_3) > 0)
{
System.out.print("found a match " +
"in group 3");
}
}
}
// This code is contributed by shikhasingrajput
Python3
# Python3 program to compare a value
# with multiple values
# Driver Code
if __name__ == '__main__':
# Create bitmasks
group_1 = (1 << 1) | (1 << 2) | (1 << 3)
group_2 = (1 << 4) | (1 << 5) | (1 << 6)
group_3 = (1 << 7) | (1 << 8) | (1 << 9)
# Values to be checked
value_to_check = 9
# Checking with created bitmask
if (((1 << value_to_check) & group_1) > 0):
print("found a match " + "in group 1")
if (((1 << value_to_check) & group_2) > 0):
print("found a match " + "in group 2")
if (((1 << value_to_check) & group_3) > 0):
print("found a match " + "in group 3")
# This code is contributed by gauravrajput1
C#
// C# program to compare a value
// with multiple values
using System;
class GFG{
// Driver Code
public static void Main(String[] args)
{
// Create bitmasks
int group_1 = (1 << 1) |
(1 << 2) |
(1 << 3);
int group_2 = (1 << 4) |
(1 << 5) |
(1 << 6);
int group_3 = (1 << 7) |
(1 << 8) |
(1 << 9);
// Values to be checked
int value_to_check = 9;
// Checking with created
// bitmask
if (((1 << value_to_check) &
group_1) > 0)
{
Console.Write("found a match " +
"in group 1");
}
if (((1 << value_to_check) &
group_2) > 0)
{
Console.Write("found a match " +
"in group 2");
}
if (((1 << value_to_check) &
group_3) > 0)
{
Console.Write("found a match " +
"in group 3");
}
}
}
// This code is contributed by gauravrajput1
Javascript
<script>
// JavaScript program to compare a value
// with multiple values
// Create bitmasks
let group_1 = (1 << 1) |
(1 << 2) | (1 << 3);
let group_2 = (1 << 4) |
(1 << 5) | (1 << 6);
let group_3 = (1 << 7) |
(1 << 8) | (1 << 9);
// Values to be checked
let value_to_check = 9;
// Checking with created bitmask
if (((1 << value_to_check) &
group_1) > 0)
{
document.write("found a match " +
"in group 1");
}
if (((1 << value_to_check) &
group_2) > 0)
{
document.write("found a match " +
"in group 2");
}
if (((1 << value_to_check) &
group_3) > 0)
{
document.write("found a match " +
"in group 3");
}
// This code is contributed by unknown2108
</script>
Producción
found a match in group 3
Nota : este enfoque funciona mejor para valores que no superan el tamaño natural de su CPU. Por lo general, sería 64 en los tiempos modernos. La solución general a este problema usando Plantilla de C++11 . A continuación se muestra el programa para el mismo:
Programa 3:
C++
// C++ program for comparing variable
// with multiples variable
#include <algorithm>
#include <initializer_list>
#include <iostream>
using namespace std;
template <typename T>
// Function that checks given variable
// v in the list lst[]
bool is_in(const T& v,
std::initializer_list<T> lst)
{
return (std::find(std::begin(lst),
std::end(lst), v)
!= std::end(lst));
}
// Driver Code
int main()
{
// Number to be compared
int num = 10;
// Compare with multiple variables
if (is_in(num, { 1, 2, 3 }))
cout << "Found in group" << endl;
else
cout << "Not in group" << endl;
// Character to be compared
char c = 'a';
// Compare with multiple variables
if (is_in(c, { 'x', 'a', 'c' }))
cout << "Found in group" << endl;
else
cout << "Not in group" << endl;
return 0;
}
Python3
# Python program for above approach
import math
# Function that checks given variable
# v in the list lst[]
def is_in(v, lst):
return v in lst
# Driver Code
# Number to be compared
num = 10
# Compare with multiple variables
if (is_in(num, [1, 2, 3] )):
print("Found in group")
else:
print("Not in group")
# Character to be compared
c = 'a'
# Compare with multiple variables
if (is_in(c, ['x', 'a', 'c'] )):
print("Found in group")
else:
print("Not in group")
#This code is contributed by shubhamsingh10
C#
// C# program for the above approach
using System;
using System.Linq;
public static class Extensions
{
// Function that checks given variable
// v in the list lst[]
public static bool is_in<T>(this T[] array,
T target)
{
return array.Contains(target);
}
}
class GFG{
// Driver Code
static public void Main ()
{
// Number to be compared
int num = 10;
int [] arr = { 1, 2, 3 };
// Compare with multiple variables
if (arr.is_in(num))
Console.WriteLine("Found in group");
else
Console.WriteLine("Not in group");
// Character to be compared
char c = 'a';
char[] arr1 = { 'x', 'a', 'c' };
// Compare with multiple variables
if (arr1.is_in(c))
Console.WriteLine("Found in group");
else
Console.WriteLine("Not in group");
}
}
// This code is contributed by shubhamsingh10
Producción
Not in group Found in group
Nota : Sin embargo, no es muy eficiente cuando no se usa con tipos primitivos. Para std::string producirá un error . Esta tarea se volvió realmente fácil con C++17 , ya que viene con Fold Expression . Esto generalmente se llama Folding , que ayuda a expresar la misma idea con menos código y funciona bien con cualquier tipo de datos. Aquí, “||” operador para reducir todos los resultados booleanos a uno solo, que solo es falso si todos los resultados de la comparación son falsos . A continuación se muestra el programa para el mismo:
Programa 4:
C++
// C++ program for comparing variable
// with multiple variables
#include <algorithm>
#include <initializer_list>
#include <iostream>
#include <string>
using namespace std;
template <typename First, typename... T>
// Function that checks given variable
// first in the list t[]
bool is_in(First&& first, T&&... t)
{
return ((first == t) || ...);
}
// Driver Code
int main()
{
// Number to be compared
int num = 10;
// Compare using template
if (is_in(num, 1, 2, 3))
cout << "Found in group" << endl;
else
cout << "Not in group" << endl;
// String to be compared
string c = "abc";
// Compare using template
if (is_in(c, "xyz", "bhy", "abc"))
cout << "Found in group" << endl;
else
cout << "Not in group" << endl;
return 0;
}
Producción:
Publicación traducida automáticamente
Artículo escrito por scorchingeagle y traducido por Barcelona Geeks. The original can be accessed here. Licence: CCBY-SA