C Programming - Library Functions
- Library Functions - General Questions
- Library Functions - Find Output of Program
- Library Functions - Point Out Errors
- Library Functions - True / False Questions
- Library Functions - Yes / No Questions
#include<stdio.h>
#include<string.h>
int main()
{
char dest[] = {97, 97, 0};
char src[] = "aaa";
int i;
if((i = memcmp(dest, src, 2))==0)
printf("Got it");
else
printf("Missed");
return 0;
}
memcmp compares the first 2 bytes of the blocks dest and src as unsigned chars. So, the ASCII value of 97 is 'a'.
if((i = memcmp(dest, src, 2))==0)
When comparing the array dest and src as unsigned chars, the first 2 bytes are same in both variables.so memcmp returns '0'.
Then, the if(0=0) condition is satisfied. Hence the output is "Got it".
The gcvt() function converts a floating-point number to a string. It converts given value to a null-terminated string.
#include <stdlib.h>
#include <stdio.h>
int main(void)
{
char str[25];
double num;
int sig = 5; /* significant digits */
/* a regular number */
num = 9.876;
gcvt(num, sig, str);
printf("string = %s\n", str);
/* a negative number */
num = -123.4567;
gcvt(num, sig, str);
printf("string = %s\n", str);
/* scientific notation */
num = 0.678e5;
gcvt(num, sig, str);
printf("string = %s\n", str);
return(0);
}
Output:
string = 9.876
string = -123.46
string = 67800
#include<stdio.h>
int main()
{
int i;
char c;
for(i=1; i<=5; i++)
{
scanf("%c", &c); /* given input is 'a' */
printf("%c", c);
ungetc(c, stdin);
}
return 0;
}
for(i=1; i<=5; i++) Here the for loop runs 5 times.
Loop 1:
scanf("%c", &c); Here we give 'a' as input.
printf("%c", c); prints the character 'a' which is given in the previous "scanf()" statement.
ungetc(c, stdin); "ungetc()" function pushes character 'a' back into input stream.
Loop 2:
Here the scanf("%c", &c); get the input from "stdin" because of "ungetc" function.
printf("%c", c); Now variable c = 'a'. So it prints the character 'a'.
ungetc(c, stdin); "ungetc()" function pushes character 'a' back into input stream.
This above process will be repeated in Loop 3, Loop 4, Loop 5.