将自定义arrayList的元素复制到字符串

Question

I am trying to put the elements from my custom arrayList to a String. But when i tried to iterate over it, it only prints the last entry. This is for a todolist app that should have the name of the task and either 1 or 0 depending on whether the task is done or not.

This is the code so far:

Entry.java

public class Entry {
String S;
boolean b;
public Entry(String S, boolean b) {
    this.S = S;
    this.b = b;
}
public String getS() {
    return S;
}

public void setS(String S) {
    this.S = S;
}

public void setB(boolean b) {
    this.b = b;
}

public boolean isB() {
    return b;
}

}

MainActivity.java

ArrayList<Entry> mEntries;
String copy;
String name1;
int i;
public String getShareData() {

    for (Entry n : mEntries) {
        name1 = n.getS();
        i = boolToInt(n.isB());
        copy = name1 + "\t" + i + "\n";
    }
    return copy;
}

public int boolToInt(boolean b) {
    return b ? 1 : 0;
}

Answer 1

That's because you are overwriting your variable for each entry, only keeping the last element. What I added on your code will append each entry at the end of the String copy.

ArrayList<Entry> mEntries;
String copy;
String name1;
int i;
public String getShareData() {
    copy = "";
    for (Entry n : mEntries) {
        name1 = n.getS();
        i = boolToInt(n.isB());
        copy += name1 + "\t" + i + "\n";
    }
    return copy;
}

public int boolToInt(boolean b) {
    return b ? 1 : 0;
}

Answer 2

You can use like below

public String getShareData() {
        copy="";
        for (Entry n : mEntries) {
            name1 = n.getS();
            i = boolToInt(n.isB());
            if(copy.length()==0)
                copy = name1 + "\t" + i + "\n";
            else
                copy = copy + name1 + "\t" + i + "\n";
        }
        return copy;
    }