Return Multiple Arrays Using for Loop Inside toString Class

问题

This is what I have so far. What this program basically does is take user input(their social security numbers), verifies that their input is in the proper format (XXX-XX-XXXX), adds the verified input to the arrays list. Now the final step is to create a toString() method that will return a human readable String representation of all social security numbers added to the array. This method must use a for loop, and must print 1 social security number entry per line. For example:

"The Social Security Numbers you entered are:
345-43-5674
456-62-8435
910-70-0053"

package SSNServerStorage;

public class SSNArray
{
    private String[] SSNNumber;
    private int arrayCount;

    public SSNArray(){
        SSNNumber = new String[300];
        arrayCount = 0;
    }

    public SSNArray(int arraySize){
        SSNNumber = new String[arraySize];
        arrayCount = 0;
    }

    public String[] getSSNNumber(){
        return SSNNumber;
    }

    public int getArrayCount(){
        return arrayCount;
    }

    public boolean validateSSNNumber(String SSNFormat){
        return SSNFormat.matches("\\d{3}-\\d{2}-\\d{4}");
    }

    public String addSSN(String SSNFormat){
        if (validateSSNNumber(SSNFormat)){
            return SSNNumber[arrayCount++] = SSNFormat;
        }else{
            return null;
        }
    }

    public String toString(){
        System.out.println("The Social Security Numbers you entered are:");

        for()
        {
            //
            //
            //
            //
        }
    }
}

回答1:

You can declare a String to concatenate all the SSNumbers.

@Override
public String toString(){
    String str = "The Social Security Numbers you entered are:\n";
    for(int x=0; x< arrayCount; x++)
        str += SSNumber[x] + "\n";
    return str;
}

Since it is a toString() method, you will want to return the string representation of the class instead of doing println().

回答2:

Your toString method doesn't have correct signature, it should return String. This should do what you need:

@Override
public String toString(){
    StringBuilder sb = new StringBuilder("The Social Security Numbers you entered are:\n");

    for (int i = 0; i < arrayCount; i++) {
        sb.append(SSNNumber[i]).append("\n");
    }

    return sb.toString();
}

Also remember to use the @Override annotation.

回答3:

Just concatenate :

@Override
public String toString(){
String s = "The Social Security Numbers you entered are:\n";
    for(int i =0; i < SSNNumber.length; i ++)
        s +=SSNNumber[i]+"\n";
    return s;
}

回答4:

StringBuilder strbul = new StringBuilder()
    for(int i=0;i<SSNNumber.length;i++)
            {
                strbul.append(SSNNumber[i]).append("\n");
            }
return strbul.toString();

来源：https://stackoverflow.com/questions/32787238/return-multiple-arrays-using-for-loop-inside-tostring-class

标签

java

arrays

loops

for-loop

tostring