C: add static-const-variable.c

c-programming/experiments/static-const-variable.c

@@ -0,0 +1,38 @@
+/*
+ * static-vs-const-variable.c
+ *
+ * Author: Intel A80486DX2-66
+ * License: Creative Commons Zero 1.0 Universal or Unlicense
+ * SPDX-License-Identifier: CC0-1.0 OR Unlicense
+ */
+
+#include <inttypes.h>
+#include <math.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifndef M_PI
+# define M_PI 3.1415926535897932384626433832795028841971693993751058209749445922
+#endif
+
+uint16_t frequently_called(uint8_t i);
+
+uint16_t frequently_called(uint8_t i) {
+	static uint16_t variable_1 = 2;
+	const uint16_t variable_2 =
+		(uint16_t) (
+			(pow(10, floor(log10(M_PI))) + pow(10, ceil(log10(M_PI)))) / 2
+		);
+	static const uint16_t variable_3 = 3;
+
+	return variable_1 * variable_2 * variable_3 * i;
+}
+
+int main(void) {
+	for (uint8_t i = 1; i <= 16; i++) {
+		printf("f(%02" PRIu8 ") = %" PRIu16 "\n", i, frequently_called(i));
+	}
+
+	return EXIT_SUCCESS;
+}