diff --git a/11-arrays.c b/11-arrays.c
new file mode 100644
index 0000000..a446f0c
--- /dev/null
+++ b/11-arrays.c
@@ -0,0 +1,26 @@
+#include <stdio.h>
+
+/* count digits, white space, others */
+int main()
+{
+	int c, i, nwhite, nother;
+	int ndigit[10];
+
+	nwhite = nother = 0;
+	for(i = 0; i < 10; ++i)
+		ndigit[i] = 0;
+
+	while ((c = getchar()) != EOF)
+		if (c >= '0' && c <= '9')
+			++ndigit[c-'0'];
+		else if (c == ' ' || c == '\n' || c == '\t')
+			++nwhite;
+		else
+			++nother;
+
+	printf("digits =");
+	for (i = 0; i < 10; ++i)
+		printf(" %d", ndigit[i]);
+	printf(", white space = %d, other = %d\n",
+		nwhite, nother);
+}