In this program, we will make a C program to print diamond patterns of numbers & a C program to print diamond patterns of stars using nested for loop and if-else statements.

## C program to print diamond pattern of number

`#include<stdio.h>int main(){    int n;    printf("Enter Number:");    scanf("%d",&n);        int i=1;        while(i<=n)    {        for(int j=1;j<=n-i;j++)            printf(" ");                for(int j=1;j<=i;j++)            printf("%d", j);                for(int j=i-1;j>0;j--)            printf("%d", j);        printf("n");        i++;    }    i=n-1;    while(i>0)    {        for(int j=1;j<=n-i;j++)        printf(" ");                for(int j=1;j<=i;j++)            printf("%d", j);                for(int j=i-1;j>0;j--)            printf("%d", j);        printf("n");        i--;    }  }`

`#include <stdio.h>int main(){    int i, j, p;    for (i = 1; i <= 5; i++)    {        p = 1;        for (j = 1; j <= 9; j++)        {            if ((j <= 5 - i) || (j >= 5 + i))            {                printf(" ");            }            else            {                printf("%d", p);                p++;            }        }        printf("n");    }    for (i = 1; i <= 4; i++)    {        p = 1;        for (j = 1; j <= 9; j++)        {            if ((j <= i) || (j >= 10 - i))            {                printf(" ");            }            else            {                printf("%d", p);                p++;            }        }        printf("n");    }    return 0;}`
Output:

## C program to print diamond pattern of star

`#include <stdio.h>int main(){    int i, j;    for (i = 1; i <= 5; i++)    {        for (j = 1; j <= 9; j++)        {            if ((j <= 5 - i) || (j >= 5 + i))            {                printf(" ");            }            else            {                printf("*");            }        }        printf("n");    }    for (i = 1; i <= 4; i++)    {        for (j = 1; j <= 9; j++)        {            if ((j <= i) || (j >= 10 - i))            {                printf(" ");            }            else            {                printf("*");            }        }        printf("n");    }    return 0;}`