Given two strings string1 and string2, the task is to check if these two strings are equal or not.
Examples:
Input: string1 = “neveropen”, string2 = “neveropen”
Output: YesInput: string1 = “Geeks for Geeks”, string2 = “Geeks for Geeks”
Output: YesInput: string1 = “neveropen”, string2 = “Geeks”
Output: NoInput: string1 = “Geeks for Geeks”, string2 = “Geeks for neveropen”
Output: No
Approach 1: Using Relational Operator
|
Programming Language |
How to check for String Equality |
|---|---|
|
C |
strcmp() |
|
C++ |
== |
|
Java |
equals() |
|
Python |
is |
| C# | == |
| JavaScript | === |
C++
// C++ code for the above approach:#include <bits/stdc++.h>using namespace std;// Drivers codeint main(){ // First string. string s1 = "neveropen"; // Second string. string s2 = "Geeks for neveropen"; // Check condition. if (s1 == s2) { cout << "Strings Are Equal" << endl; } else { cout << "Strings Are Not Equal" << endl; } return 0;} |
Java
import java.util.*;public class Main { public static void main(String[] args) { // first string String s1 = "neveropen"; // second string String s2 = "Geeks for neveropen"; // check condition if (s1.equals(s2)) { System.out.println("Strings Are Equal"); } else { System.out.println("Strings Are Not Equal"); } }} |
Python
# Python3 program to check 2 strings are identical or notif __name__ == "__main__": # first string.string1 = "neveropen"# second string.string2 = "Geeks for neveropen"# check conditionif (string1 is string2): print("Strings Are Equal")else: print("Strings Are Not Equal") |
C#
using System;class GFG { static void Main(string[] args) { // first string string s1 = "neveropen"; // second string string s2 = "Geeks for neveropen"; // check condition if (s1 == s2) { Console.WriteLine("Strings Are Equal"); } else { Console.WriteLine("Strings Are Not Equal"); } }} |
Javascript
// js code implementationconst s1 = "neveropen";const s2 = "Geeks for neveropen";if (s1 === s2) { console.log("Strings Are Equal");} else { console.log("Strings Are Not Equal");} |
Output
Strings Are Not Equal
Approach 2: Using Comparator
Define a function to compare values with the following conditions:
- Given strings are equal if:
- both the strings are equal lexicographically, i.e.(string1 == string2) it returns 0.
- Given strings are not equal if :
- (string1 > string2) it returns a positive value.
- (string1 < string2) it returns a negative value.
The value is calculated as (int)str1.charAt(i) – (int)str2.charAt(i)
Below is the implementation for the above approach:
C++
// C++ program to Compare two strings// lexicographically#include <bits/stdc++.h>using namespace std;// This function compares two strings// lexicographically without using// library functionsint stringCompare(const string& str1, const string& str2){ int l1 = str1.length(); int l2 = str2.length(); int lmin = min(l1, l2); for (int i = 0; i < lmin; i++) { int str1_ch = (int)(str1[i]); int str2_ch = (int)(str2[i]); if (str1_ch != str2_ch) { return str1_ch - str2_ch; } } // Edge case for strings like // String1 = "Geeks" and // String2 = "Geeksforneveropen" if (l1 != l2) { return l1 - l2; } // If none of the above conditions // is true, it implies both the // strings are equal else { return 0; }}void isEqual(const string& str1, const string& str2){ int compareStrings = stringCompare(str1, str2); bool result = (compareStrings == 0) ? true : false; // Comparing for String 1 < String 2 cout << "Comparing " << str1 << " and " << str2 << ": "; if (result) cout << "Equal" << endl; else cout << "Not equal" << endl;}int main(){ string string1 = "Geeksforneveropen"; string string2 = "Practice"; string string3 = "Geeks"; string string4 = "Geeks"; // Comparing for String 1 < String 2 isEqual(string1, string2); // Comparing for String 3 = String 4 isEqual(string3, string4); // Comparing for String 1 > String 4 isEqual(string1, string4); return 0;}// This code is contributed by Prasad264 |
Java
// Java program to Compare two strings// lexicographicallypublic class GFG { // This method compares two strings // lexicographically without using // library functions public static int stringCompare(String str1, String str2) { int l1 = str1.length(); int l2 = str2.length(); int lmin = Math.min(l1, l2); for (int i = 0; i < lmin; i++) { int str1_ch = (int)str1.charAt(i); int str2_ch = (int)str2.charAt(i); if (str1_ch != str2_ch) { return str1_ch - str2_ch; } } // Edge case for strings like // String1 = "Geeks" and // String2 = "Geeksforneveropen" if (l1 != l2) { return l1 - l2; } // If none of the above conditions // is true, it implies both the // strings are equal else { return 0; } } public static void isEqual(String str1, String str2) { int compareStrings = stringCompare(str1, str2); Boolean result = (compareStrings == 0) ? true : false; // Comparing for String 1 < String 2 System.out.print("Comparing " + str1 + " and " + str2 + ": "); if (result) System.out.println("Equal"); else System.out.println("Not equal"); } // Driver function to test the above program public static void main(String args[]) { String string1 = new String("Geeksforneveropen"); String string2 = new String("Practice"); String string3 = new String("Geeks"); String string4 = new String("Geeks"); // Comparing for String 1 < String 2 isEqual(string1, string2); // Comparing for String 3 = String 4 isEqual(string3, string4); // Comparing for String 1 > String 4 isEqual(string1, string4); }} |
Python3
# This function compares two strings# lexicographically without using# library functionsdef stringCompare(str1, str2): l1 = len(str1) l2 = len(str2) lmin = min(l1, l2) for i in range(lmin): str1_ch = ord(str1[i]) str2_ch = ord(str2[i]) if str1_ch != str2_ch: return str1_ch - str2_ch # Edge case for strings like # String1 = "Geeks" and # String2 = "Geeksforneveropen" if l1 != l2: return l1 - l2 # If none of the above conditions # is true, it implies both the # strings are equal else: return 0def is_equal(str1, str2): compare_strings = stringCompare(str1, str2) result = compare_strings == 0 # Comparing for String 1 < String 2 print(f"Comparing {str1} and {str2}: ", end="") if result: print("Equal") else: print("Not equal")string1 = "Geeksforneveropen"string2 = "Practice"string3 = "Geeks"string4 = "Geeks"# Comparing for String 1 < String 2is_equal(string1, string2)# Comparing for String 3 = String 4is_equal(string3, string4)# Comparing for String 1 > String 4is_equal(string1, string4) |
C#
// C# Codeusing System;public class GFG{ // This method compares two strings // lexicographically without using // library functions public static int StringCompare(string str1, string str2) { int l1 = str1.Length; int l2 = str2.Length; int lmin = Math.Min(l1, l2); for (int i = 0; i < lmin; i++) { int str1_ch = (int)str1[i]; int str2_ch = (int)str2[i]; if (str1_ch != str2_ch) { return str1_ch - str2_ch; } } // Edge case for strings like // String1 = "Geeks" and // String2 = "Geeksforneveropen" if (l1 != l2) { return l1 - l2; } // If none of the above conditions // is true, it implies both the // strings are equal else { return 0; } } public static void IsEqual(string str1, string str2) { int compareStrings = StringCompare(str1, str2); bool result = (compareStrings == 0) ? true : false; // Comparing for String 1 < String 2 Console.Write("Comparing " + str1 + " and " + str2 + ": "); if (result) Console.WriteLine("Equal"); else Console.WriteLine("Not equal"); } // Driver function to test the above program public static void Main(string[] args) { string string1 = "Geeksforneveropen"; string string2 = "Practice"; string string3 = "Geeks"; string string4 = "Geeks"; // Comparing for String 1 < String 2 IsEqual(string1, string2); // Comparing for String 3 = String 4 IsEqual(string3, string4); // Comparing for String 1 > String 4 IsEqual(string1, string4); }} |
Javascript
function stringCompare(str1, str2) { const l1 = str1.length; const l2 = str2.length; const lmin = Math.min(l1, l2); for (let i = 0; i < lmin; i++) { const str1_ch = str1.charCodeAt(i); const str2_ch = str2.charCodeAt(i); if (str1_ch !== str2_ch) { return str1_ch - str2_ch; } } // Edge case for strings with different lengths if (l1 !== l2) { return l1 - l2; } // If none of the above conditions is true, it implies both strings are equal return 0;}function isEqual(str1, str2) { const compareStrings = stringCompare(str1, str2); const result = compareStrings === 0; console.log(`Comparing ${str1} and ${str2}: ${result ? 'Equal' : 'Not equal'}`);}const string1 = "Geeksforneveropen";const string2 = "Practice";const string3 = "Geeks";const string4 = "Geeks";// Comparing for String 1 < String 2isEqual(string1, string2);// Comparing for String 3 = String 4isEqual(string3, string4);// Comparing for String 1 > String 4isEqual(string1, string4); |
Output
Comparing Geeksforneveropen and Practice: Not equal Comparing Geeks and Geeks: Equal Comparing Geeksforneveropen and Geeks: Not equal
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