Print first and last character of each word in a string

Introduction

A C++ string is contiguous storage of alphanumeric characters as well as special characters. A string has the following properties −

• Every C++ string is associated with a fixed length.

• Character operations can be easily performed with the string characters.

• A string is composed of words, which are space separated.

In this article, we are going to develop a code that takes as input a string, and displays the last character of each word in the string. Let us look at the following example to understand the topic better −

Sample Example

Example 1 −

str − “Key word of a string”
Output − Ky wd of aa sg

For instance, in the fourth word of this string, only a single character “a” occurs, therefore this is the first and last character of this string.

In this article, we will develop a code to extract the last character of each word using indexing operator. Here, we will develop a code to extract the last character of each word using indexing operator ,and then accessing the characters at the subsequent previous characters respectively.

Syntax

str.length()

length()

The length() method in C++ is used to compute the number of characters in the string. The in-built length() method works in linear time.

Algorithm

• An input string, str is accepted.

• The length of the string is computed using the length() method, and stored in the len variable.

• An iteration of the string is performed, using the for loop i.

• The particular character of string is extracted and stored in the variable ch.

• Each time the character at ith position is extracted

• If this index is equivalent to the first index of the string, it is printed

• If this index is equivalent to the last index of the string,then len-1 character, is displayed.

• If this character is equivalent to the space character, then the i-1th index character is displayed, since it is the last character of the previous word.

• The i+1th index is also printed owing to the first character of the next word respectively.

Example

The following C++ code snippet is used to take as input a sample string and compute the first and last character of each word in the string −

//including the required libraries
#include<bits/stdc++.h>
using namespace std;
//compute the first and last characters of a string 
void  wordfirstandlastchar(string str) {
   // getting length of the string 
   int len = str.length();
    
   for (int i = 0; i <len ; i++) {
      char ch = str[i];
      //print the first word of the string 
      if (i == 0)
         cout<<ch;
 
      //last word of the string
      if (i == len - 1)
         cout<<ch;
 
      //if a space is encountered, marks the start of new word 
      if (ch == ' ') {
         //print the previous character of the last word 
         //print the next character of the next word 
         char lst = str[i-1];
         char nxt = str[i+1];
         cout<<lst<<" "<<nxt;
      }
   }
}
 
//calling the method
int main() {
   //taking a sample string 
   string str = "I want to learn at TutorialsPoint";
   cout<<"Input String : "<< str <<"\n"; 
   //getfirstandlast characters
   cout<<"First and last words of each string : \n";
   wordfirstandlastchar(str);
}

Output

Input String − I want to learn at TutorialsPoint
First and last words of each string − 
II wt to ln at Tt

Conclusion

Most of the character manipulation operations in C++ strings can be performed using a single traversal of the string. The characters of the string can be easily accessed using their positions in constant time. The indexes of the string begin with 0 and end with the string length-1 value.