Given the code fragment:
double discount = 0;
int qty = Integer.parseInt(args[0]);
// line n1;
And given the requirements:
If the value of the qty variable is greater than or equal to 90, discount = 0.5
If the value of the qty variable is between 80 and 90, discount = 0.2
If the value of the qty variable is between 80 and 90, discount = 0.2
Which two code fragments can be independently placed at line n1 to meet the requirements?
A.
if (qty >= 90) {discount = 0.5; }
if (qty > 80 && qty < 90) {discount = 0.2; }
B.
discount = (qty >= 90) ? 0.5 : 0;
discount = (qty > 80) ? 0.2 : 0;
C.
discount = (qty >= 90) ? 0.5 : (qty > 80) ? 0.2 : 0;
D.
if (qty > 80 && qty < 90) {
discount = 0.2;
} else {
discount = 0;
}
if (qty >= 90) {
discount = 0.5;
} else {
discount = 0;
}
E.
discount = (qty > 80) ? 0.2 : (qty >= 90) ? 0.5 : 0;
題解
選項A，程式邏輯符合題義。
選項B，qty若大於等於90，那它一定會大於80，因此第7行程式沒有作用，會被第8行的結果覆蓋。
選項C，程式邏輯符合題義。
選項D，qry若介於80到90之間，discount會在第二個if結構中，數值被改成0。
選項E，qty若大於等於90，那它一定會大於80，因此第二個三元條件運算子條件永遠不會成立。