local variable and global variable

c-basic/local_vs_global.c

@@ -0,0 +1,19 @@
+#include <stdio.h>
+
+int main()
+{
+  int a;
+
+  {
+    int b;
+
+    b = 20;
+    a = 10;
+
+    printf("a = %d, b = %d\n", a, b);
+    
+  }
+
+  printf("a = %d\n", a); // correct
+  //  printf("b = %d\n", b); // incorrect/error
+}