check if a string is palindrome c++ code example

Example 1: check if a string is palindrome cpp

// Check whether the string is a palindrome or not.
#include <bits/stdc++.h>

using namespace std;

int main(){
    string s;
    cin >> s;
    
    int l = 0;
    int h = s.length()-1;

    while(h > l){
        if(s[l++] != s[h--]){
            cout << "Not a palindrome" << endl;
            return 0;
        }
    }
    cout << "Is a palindrome" << endl;
    return 0;

}

Example 2: Write a function that tests whether a string is a palindrome

def palindrome_check(string):
    string = list(string)
    tmp = []
    #remove any spaces
    for x in range(0, len(string)):
        if(string[x] != " "):
            tmp.append(string[x].lower())
    
            
    #now reverse the string
    array1 = []
    i = 0
    j = len(tmp)-1

    while(i < len(tmp)):
        array1.append(tmp[j])
        i += 1
        j -= 1

    #check if array1 is equal to the string
    counter = 0
    for x in range(0, len(tmp)):
        if(tmp[x] == array1[x]):
            counter += 1

    #if the counter is equal to the length of the string then the word
    #is the same
    if(counter == len(tmp)):
        return True
    
    return False

Example 3: check if palindrome

function isPalindrome(str) {
  str = str.toLowerCase();
  return str === str.split("").reverse().join("");
}

Example 4: palindrome c++

#include<iostream>
#include<string>
#include<algorithm>
bool IsPalindrome_true_false(const std::string& );
int main ()
{
    
    std::cout<<"Please enter a string:\t";
    std::string str;
    getline(std::cin, str);
    
    // convert the string from uppercase to lowercase 
    int i = 0;
    while(str[i])
    {
        if(str[i] == std::toupper(str[i]) && std::isalpha(str[i]) == 1024)
        str[i]+= 32;
        ++i;
    }
    // looping while string is empty 
    while(str.empty())
    {
        std::cout<<"\nPlease enter a string your string is empty:\t";
        if(!str.empty())
        std::string str;
        getline(std::cin, str);
    }
    
    std::cout<<"\n"<<std::boolalpha<<IsPalindrome_true_false(str)<<std::endl;
    std::cout<<std::endl;

    return 0;
}

// check if string is a palindrome and return true or false 
bool IsPalindrome_true_false(const std::string& str)
{

    int i = 0;                
    int j = str.length() - 1; 

    while(i <= j )
    {   
        
        if(std::isalpha(str[i]) == 0){
            ++i;
            continue;
        }else if(std::isalpha(str[j]) == 0){
            --j;
            continue;
        }   
        if(str[i] != str[j]){
        
           return false;
        }
        ++i;
        --j;
    }  
    return true;
}