diff --git a/C/uninon.c b/C/uninon.c
new file mode 100644
index 0000000..ccf4dc5
--- /dev/null
+++ b/C/uninon.c
@@ -0,0 +1,27 @@
+//sizeof() an union example
+
+#include<stdio.h>
+void main()
+{
+    int a;
+    float b;
+    struct student_details
+    {
+        char name[20];
+        int regno;
+    }student;
+    
+    union code
+    {
+        int x;
+        char c;
+        float y;
+    }sample;
+    
+    printf("size of variable a=%d\n",sizeof(a));
+    printf("size of variable b=%d\n",sizeof(b));
+    printf("size of structure variable is %d\n",sizeof(student));
+    printf("size of union variable is %d\n",sizeof(sample));
+    printf("size of integer is %d\n",sizeof(int));
+    
+}
\ No newline at end of file