- Write a C program to delete all vowels from a string.
In this C program, we will delete all vowel alphabets from a string. There are five vowel alphabets in english A, E, I, O and U. We have to delete all vowel characters from a string. If Input string is "techcrashcourse" then output should string should be "tchcrshcrs" after removing all occurrences of vowels.
C program to remove vowels from string
In this program, we first take a string as input from user using gets function. Here we are using another array to store the output string. This program uses a user defined function isVowel that takes a character as input and decide whether input character is vowel or not. Function isVowel converts upper case characters to lowercase and then perform vowel check.
We traverse from first character to last character of input string and check whether current character is vowel or not. If it is not a vowel then we copy this character to output string otherwise skip this character. At last we add a null character at the end of output string, now output string contains all input string characters except vowels.
#include <stdio.h>
#include <string.h>
int isVowel(char ch);
int main(){
char inputString[100], outputString[100];
int readIndex, writeIndex = 0;
printf("Enter a string \n");
gets(inputString);
for(readIndex = 0;inputString[readIndex]!='\0';readIndex++){
if(!isVowel(inputString[readIndex])){
outputString[writeIndex++] = inputString[readIndex];
}
}
outputString[writeIndex] = '\0';
printf("Input String: %s \n", inputString);
printf("String without Vowels: %s \n", outputString);
return 0;
}
int isVowel(char ch){
if((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z')){
if(ch >= 'A' && ch <= 'Z'){
ch = ch + ('a' - 'A');
}
/* Check if character(ch) is a vowel */
if (ch == 'a' || ch == 'e' || ch == 'i' ||
ch == 'o' || ch == 'u'){
return 1;
}
}
return 0;
}
Output
Enter a string delete vowels Input String: delete vowels String without Vowels: dlt vwls
C program to delete vowels from string without using extra memory
In this program, we don't use any extra character array to store the output string without vowels. We will modify input string and delete all vowels in single pass.
#include <stdio.h>
int isVowel(char ch);
int main(){
char inputString[100];
int readIndex, writeIndex = 0;
printf("Enter a string \n");
gets(inputString);
for(readIndex = 0;inputString[readIndex]!='\0';readIndex++){
if(!isVowel(inputString[readIndex])){
inputString[writeIndex++] = inputString[readIndex];
}
}
inputString[writeIndex] = '\0';
printf("String without Vowels: %s \n", inputString);
return 0;
}
int isVowel(char ch){
if((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z')){
if(ch >= 'A' && ch <= 'Z'){
ch = ch + ('a' - 'A');
}
/* Check if character(ch) is a vowel */
if (ch == 'a' || ch == 'e' || ch == 'i' ||
ch == 'o' || ch == 'u'){
return 1;
}
}
return 0;
}
Output
Enter a string without extra memory String without Vowels: wtht xtr mmry
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