Thread: How to take a string input and remove whitespace?

Well there's this:

Code:

scanf("%30s", buffer)

where 31 is the size of your buffer array.

That will fill buffer with a string without whitespace.


You can also use strchr() to find specific white space characters in a string.

You could just shift the remainder of the string to the left to cover any spaces:

Code:

#include <string.h>  /* For memmove(). */
#include <ctype.h>  /* For isspace(). */
#include <stddef.h>  /* For size_t. */

void remove_whitespace(char *str) {
    char *p;
    size_t len = strlen(str);

    for(p = str; *p; p ++, len --) {
        while(isspace(*p)) memmove(p, p+1, len--);
    }
}

Note that I haven't tested that.

Hi there! i recently made an RPN calculator for my stack and queue project.

here's how i did it:

you declare and define void push(char* s[], stack* S), char* pop(stack* S), void enqueue(char * s[], queue* Q), char * dequeue(queue* Q) first you know, among all the other functions you will need then, create stack pointer S, queue pointer Q, malloc them properly, and then: (psedocode only)

1.) you accept user input (with whitespace) into char postfix[MAX]
2.) you declare and initialize a string s[MAX]=" ", and another char pointer *p, then malloc it properly.
3.) you use strtok():

Code:

	p=strtok(postfix,s);
                enqueue(p, Q);
	while((p=strtok(NULL, s)) != NULL) {/*separates the string into individual tokens*/
		enqueue(p, Q);  /*stores the tokens as strings in the queue*/
	}

so the string tokens of your infix expression should be stored in the queue. after which you can then dequeue() and then do whatever you want with the string tokens.

of course this only works if there are spaces between the tokens. if there are cases where there are no spaces, just add loop and if-else statements to separate those tokens without spaces between them.

have fun!

I don't see how whitespace is an issue. Pull your token off the input. You're either processing "words", or "characters". If characters, simply ignore that character if it's whitespace. If words, you already know how to pull without whitespace, or you wouldn't have the concept of a "word".


Quzah.