Null character
Updated: 07/31/2022 by Computer Hope
A null character is programming code representing a character with no value, a missing value, or used to denote the end of a character string. In databases and spreadsheets, a null character can also be used as padding. An example of a null character is when a software developer declares a variable without specifying a value, or sets it equal to nothing.
Null character examples in coding
Below are examples of null characters used in the C and JavaScript programming languages.
Example code in C
#include <stdio.h>
#include <string.h>
int main ()
{
char str[] = "computerhope";
printf("As a string:\n");
printf("%s\n",str);
printf("As an array of characters (character, decimal value of character):\n");
printf("'%c' %d\n",str[0],str[0]);
printf("'%c' %d\n",str[1],str[1]);
printf("'%c' %d\n",str[2],str[2]);
printf("'%c' %d\n",str[3],str[3]);
printf("'%c' %d\n",str[4],str[4]);
printf("'%c' %d\n",str[5],str[5]);
printf("'%c' %d\n",str[6],str[6]);
printf("'%c' %d\n",str[7],str[7]);
printf("'%c' %d\n",str[8],str[8]);
printf("'%c' %d\n",str[9],str[9]);
printf("'%c' %d\n",str[10],str[10]);
printf("'%c' %d\n",str[11],str[11]);
printf("'%c' %d\n",str[12],str[12]);
return 0;
}
Example output from C
Example code in JavaScript
<!DOCTYPE html>
<html>
<head>
<title>Null Character Example</title>
</head>
<body>
<h3>Null Character Example</h3>
<script>
let c;
document.write("<p>'" + c + "'</p>"); // undefined
c = "\0";
document.write("<p>'" + c + "' " + c.length + "</p>"); // null
c = "computerhope";
document.write("<p>'" + c + "' " + c.length + "</p>"); // computerhope without a null character
c = "computerhope\0";
document.write("<p>'" + c + "' " + c.length + "</p>"); // computerhope with a null character
</script>
</body>
</html>
Example output from JavaScript
Blank, Empty, Nbsp, Non-printing character, Null, Null pointer, Programming terms, Undefined