Error(s):

source_file.c: In function ‘main’:
source_file.c:47:24: error: expected ‘(’ before ‘studentID’
                     if studentID[i] == id){
                        ^
source_file.c:47:24: warning: statement with no effect [-Wunused-value]
source_file.c:47:42: error: expected statement before ‘)’ token
                     if studentID[i] == id){
                                          ^
source_file.c:49:38: error: ‘i’ undeclared (first use in this function)
                     average= ((exam1[i]+exam2[i]+exam3[i]+exam4[i])/4)
                                      ^
source_file.c:49:38: note: each undeclared identifier is reported only once for each function it appears in
source_file.c:52:17: error: expected ‘;’ before ‘}’ token
                 }
                 ^
source_file.c:48:25: warning: variable ‘average’ set but not used [-Wunused-but-set-variable]
                     int average;
                         ^
source_file.c:45:12: warning: unused variable ‘id’ [-Wunused-variable]
        int id = 4002;
            ^