📝 Added sandbox (code sketchbook)

sandbox/assert.c

@@ -0,0 +1,21 @@
+/* https://www.tutorialspoint.com/c_standard_library/c_macro_assert.htm */
+
+#include <assert.h>
+#include <stdio.h>
+
+int main() {
+    int a;
+    char str[50];
+
+    printf("Enter an integer value: ");
+    scanf("%d", &a);
+    assert(a >= 10);
+    printf("Integer entered is %d\n", a);
+
+    printf("Enter string: ");
+    scanf("%s", str);
+    assert(str != NULL);
+    printf("String entered is: %s\n", str);
+
+    return(0);
+}