Question

C++ Help: Given the following code int num[30] = {2, 4, 6, 9, 5, -1, 7, 10}; Show the value of: a. num[3] + num[4] b. num[6] c. num[9] + 1 d. num[30]

Answer 1

In c++

array index starts from 0

so num[0] will give the first element of array named num so num[0] = 2 that is first element of array .

similarly num[1] will give the second element of the array named num . so num[1] = 4

now

(A) num[3] + num[4] will add index numbered 3 and 4 element of array num .

now num[3] = 9 and num[4] = 5

so num[3] + num[4] will gve 9+5 = 14

now for part B

num[6] will give the element at the 6th index in array num which is equal 7

now for part c  

since array size given is 30 and only 8 elements has been initialized . By default the remaining 22 elements ( 30 - 8) will

be implicitly initialized with value 0 .

we have num[9] + 1 . Now num[9] value will be by default 0 so adding( 0 + 1 ) result will be 1 .

now D

array size given is 30 elements int num[30]. so the valid index will be from 0 to 29 . so accessing array index 30 will display any garbage value which might be present in location of num(30).