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[英]Iterating through an ArrayList of Objects and printing each variable from each object
[英]Iterating through ArrayList - not printing anything
所以我需要創建一個ArrayList,只接受那些...
然后將其添加到列表中
我想這就是我的代碼在做什么,但它沒有打印任何內容。 由於它沒有出現任何錯誤,因此使我相信它並沒有真正遍歷它。 或者它遍歷第一個(不符合條件)並停止,因此將沒有任何可打印的內容。 Ive查找了其他示例,並嘗試實現和更改一些內容,但仍然無法正常工作。 對我來說,它似乎應該工作,所以我不知道要更改什么。
任何建議將不勝感激!
import java.util.ArrayList;
public class Candidate extends AddressBook {
private boolean innovation;
private double grade;
private double regulation;
private String communication;
public Candidate(String fn, String ln, double grade, String comm,
boolean innov, double reg) {
super(fn, ln);
this.grade = grade;
this.communication = comm;
this.innovation = innov;
this.regulation = reg;
}
public boolean isInnovative() {
return innovation;
}
public double getGrade() {
return grade;
}
public double getRegulation() {
return regulation;
}
public String getCommunication() {
return communication;
}
public static ArrayList<Candidate> getEligibleCandidates(Candidate[] cands) {
ArrayList<Candidate> eligibleCandidates = new ArrayList<Candidate>();
Candidate person = cands[0];
for (Candidate i : cands) {
while (i.getGrade() < 85) {
if (i.getRegulation() >= 0.5) {
if (i.getCommunication().equals("average")
|| i.getCommunication().equals("excellent")) {
person = i;
eligibleCandidates.add(i);
}
}
}
}
return eligibleCandidates;
}
public void setCommunication(String comm) {
this.communication = comm;
}
public void setGrade(double grade) {
this.grade = grade;
}
public void setInnovation(boolean innov) {
this.innovation = innov;
}
public void setRegulation(double reg) {
this.regulation = reg;
}
public static void main(String[] args) {
Candidate r1 = new Candidate("Elena", "Brandon", 82.30, "poor", true,
0.5);
Candidate r2 = new Candidate("Thomas", "Molson", 85.10, "poor", false,
1.0);
Candidate r3 = new Candidate("Hamilton", "Winn", 77.77, "average",
false, 0.8);
Candidate r4 = new Candidate("Suzie", "Sarandin", 69.93, "average",
false, 0.0);
Candidate r5 = new Candidate("Philip", "Winne", 93.03, "average", true,
1.0);
Candidate r6 = new Candidate("Alex", "Trebok", 88.61, "poor", true, 0.7);
Candidate r7 = new Candidate("Emma", "Pivoto", 55.99, "excellent",
false, 0.8);
Candidate r8 = new Candidate("John", "Lenthen", 87.49, "excellent",
true, 0.9);
Candidate r9 = new Candidate("James", "Lean", 88.00, "excellent",
false, 0.5);
Candidate r10 = new Candidate("Jane", "Ostin", 91.20, "average", true,
0.6);
Candidate r11 = new Candidate("Emily", "Car", 66.79, "excellent",
false, 0.3);
Candidate r12 = new Candidate("Daniel", "", 76.65, "average", true, 0.2);
Candidate r13 = new Candidate("Neda", "Bazdar", 55.89, "excellent",
true, 0.5);
Candidate r14 = new Candidate("Aaron", "Smith", 90.01, "excellent",
false, 0.3);
Candidate r15 = new Candidate("Kate", "Hen", 87.9, "poor", false, 0.8);
Candidate[] cands = { r1, r2, r3, r4, r5, r6, r7, r8, r9, r10, r11,
r12, r13, r14, r15 };
ArrayList<Candidate> people = Candidate.getEligibleCandidates(cands);
System.out.println(people);
}
}
它停止了,因為
for (Candidate i : cands) {
while (i.getGrade() < 85) {
if (i.getRegulation() >= 0.5) {
if (i.getCommunication().equals("average")
|| i.getCommunication().equals("excellent")) {
person = i;
eligibleCandidates.add(i);
}
}
}
}
考慮一下它一旦進入(i.getGrade()<85),它就不會更改條件的值以使其脫離循環。 這將是無窮無盡的for循環。 您需要將其更改為if語句
for (Candidate i : cands) {
if (i.getGrade() < 85) {
if (i.getRegulation() >= 0.5) {
if (i.getCommunication().equals("average")
|| i.getCommunication().equals("excellent")) {
person = i;
eligibleCandidates.add(i);
}
}
}
}
一旦您的代碼進入while (i.getGrade() < 85)
它就永遠不會退出。 那應該是一個if
檢查,而不是一個循環。 在該loop
內,您永遠不會更改要檢查的人,因此一旦它成為真,它將永遠永遠為真。
例如,使用“ Elena”,將執行循環並檢查is Elena's grade < 85?
。 既然如此,它將進入循環。 然后,一旦循環完成處理,它將返回循環頂部並檢查, is Elena's grade STILL less than 85?
,這是正確的,因為它從未在循環中更改過。
您應該使用if
檢查,如下所示。
for (Candidate currentCandidate : cands) {
if(currentCandidate.getGrade()<85 && currentCandidate.getRegulation() >= 0.5 && (currentCandidate.getCommunication().equals("average") || currentCandidate.getCommunication().equals("excellent"))){
eligibleCandidates.add(currentCandidate);
}
}
它應該是:
if ((i.getGrade() < 85) &&
(i.getRegulation() >= 0.5) &&
(i.getCommunication().equals("average") || i.getCommunication().equals("excellent"))) {
person = i;
eligibleCandidates.add(i);
}
}
}
...而不是while ...
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