Shuffle characters in an array in C programming - c

Question

Using an online tutorial I worked on trying to shuffle characters in an array. The tutorial I used was using integers and also didn't include any user input, but when I try and replicate it and change it to do what I would like in the code I made below something is not working out.
There is no error message at all. When I run the program it only prompts the user to enter a word and then ends.
Just in case you can't understand what I wanted from the code I would like the user to be able to insert a word and then the 'shuffled' word is printed at the end. (ex. Hello > elHol)
I am still a very new programmer and have a very hard time with the subject in general so please understand any 'dumb' mistakes you'll likely come across that I've made.
Thanks in advance for any help!
#include <stdio.h>
#include <time.h>
int main ()
{
char word[15];
int i,length,j, temp;
srand(time(NULL));
printf("Insert word\n");
scanf("%s", word);
for(i=0; word[i] != '\0'; )
{
i = i + 1;
}
i = length;
for(i = 0; i < length; i++)
{
j = (rand()%length);
temp = word[i];
word[i] = word[j];
word[j] = temp;
}
for(i=0; i<length; i++)
{
printf("%c", word[i]);
}
}

Answer 1

Welcome ;). In addition to the other engineers's solution to your problem, I have modified your code not to use the temporary variable to swap.[ since you mentioned new programmer, i felt this should help to some extend. ;) ]
Look at the below source code.
#include <stdio.h>
#include <time.h>
#include <stdlib.h>
int main ()
{
char word[15];
int i,length,j, temp;
srand(time(NULL));
printf("Insert word\n");
scanf("%s", word);
for(length=0; word[length++] != '\0';);
for(i = 0; i < length; i++)
{
j = (rand()%length);
word[i] = word[i] ^ word[j];
word[j] = word[i] ^ word[j];
word[i] = word[i] ^ word[j];
}
for(i=0; i<length; i++)
{
printf("%c", word[i]);
}
}

Answer 2

Few changes to your code:
Make temp as char :
char temp;
Assign length to i you are doing it the other way where you are assigning i to length and since length is uninitialized and you are using it this value to assign to some other variable causes undefined behavior.
length = i;

Answer 3

Try my revision of your code!
This will fix the spaces and lost of vowels in printing the shuffle string. SORRY FOR MY BAD ENLISH :)
#include<stdio.h>
#include<stdlib.h>
int main(){
char word[100];
srand(time(NULL));
int i,j,length,temp;
printf("Enter a string: ");
scanf("%s",&word);
for(i = 0; word[i] != '\0'; ++i){
length = i;
}
length+=1;
i = length;
while(--i>0){
j = (rand()%length);
temp= word[j];
word[j]= word[i];
word[i]= temp;
}
for(i=0; i<=length; i++)
{
printf("%c", word[i]);
}
}