answer questions on the c program

1 files changed, 49 insertions, 1 deletions

diff --git a/README.md b/README.md
index 868f2c2..7a817b8 100644
--- a/README.md
+++ b/README.md
@@ -331,11 +331,59 @@ Your program must have declaration statements, such as float c, f;
 **Delete the semicolon from the end of the statement.**  Recompile and report the kind of error.
 The C compiler often provides cryptic error messages.  Interpret this message.
 
+The compiler error is the following:
+
+```bash
+も make
+cc -Wall -g -std=c99 -Isrc -c src/temperature.c
+src/temperature.c: In function ‘main’:
+src/temperature.c:5:3: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘printf’
+    5 |   printf("Degrees in Celsius?\n");
+      |   ^~~~~~
+src/temperature.c:8:3: error: ‘f’ undeclared (first use in this function)
+    8 |   f = 9*c/5 + 32;
+      |   ^
+src/temperature.c:8:3: note: each undeclared identifier is reported only once for each function it appears in
+make: *** [Makefile:14: temperature.o] Error 1
+```
+
+It states that a `;` colon is missing from before line 5 to terminate
+the previous line.
+
 **Change the float c, f; statement to (float c; char f;)**
 
-* Do you get any errors during compilation?
+Do you get any errors during compilation?
+
+No. I do get a compiler warning, but not an error.
+```bash
+も make
+cc -Wall -g -std=c99 -Isrc -c src/temperature.c
+src/temperature.c: In function ‘main’:
+src/temperature.c:9:35: warning: format ‘%f’ expects argument of type ‘double’, but argument 2 has type ‘int’ [-Wformat=]
+    9 |   printf("Degrees in Fahrenheit: %f\n", f);
+      |                                  ~^     ~
+      |                                   |     |
+      |                                   |     int
+      |                                   double
+      |                                  %d
+cc -Wall -g -std=c99 -Isrc -o ./bin/temperature temperature.o
+./bin/temperature
+Degrees in Celsius?
+100
+Degrees in Fahrenheit: 0.000000
+```
+
 * What are they and why?
+
+The compiler warning says that the `%f` format specifier was expecting a
+type of double, but received a type of `int`. The `char f` is being
+interpreted as a memory address rather than a value.
+
 * Do you see any difference between running this program and the earlier version? Why?
+
+Yes, the output is now incorrect because the value for `f` is coming
+from the memory address instead of the value.
+
 * If your program uses a `cout` statement, then replace it with a `printf` statement that does the same thing and vice versa.
 * If you have used neither `cout` nor `printf` in the first version, then replace what you have with `printf`.