Thread: Help with code for converting 4 digit string to integer

Hey i was just wondering if someone cold help me with this code to convert a 4 digit string into an integer ad vice versa. I have the instance variables and stuff but i think some of my code is in the wrong place.

sorry if the code doesn't come out right

I am pretty sure the int2string and string2int are in the wrong place but correct me if I am wrong.

Thanks in advance

/**
 * The Convert4Positions class will convert a string of length four
 * into a positive integer, and a positive integer into string of
 * length four. The radix of the string is specified with the
 * a Convert4Positions object is created.
 *
 * @author Daniel Stratton
 */
public class Convert4Positions {
    private int radix;
 
    /**
     * Construct a Convert4Positions object with the specified 
     * radix.
     * @param radix the radix for the conversions.
     */
    public Convert4Positions( int radix ) {
        Convert4Positions decimal = new Convert4Positions( 10 );
        assert decimal.int2string( 8976 ).equals( "8976" );
	assert decimal.string2int( "6384" ) == 6384;
	Convert4Positions octal = new Convert4Positions( 8 );
	assert octal.int2string( 01777 ).equals( "1777" );
	assert octal.string2int( "02534" ) == 2534;
        Convert4Positions binary = new Convert4Positions( 2 );
	assert binary.int2string( 1101 ).equals( "1101" );
	assert binary.string2int( "1001" ) == 1001;
    }
 
    /**
     * int2string converts an integer to 4 position string.
     *
     * @param value, the value to convert
     * @return a string with four digits that represents the integer
     */
    public String int2string( int value ) {
        // hint: see Character.forDigit
        String str = "";
 
        return str;
    }
 
    /**
     * string2int converts a string of length four into an integer.
     * The class uses the defined radix for the converion.
     *
     * @param str, the string to convert
     * @return the integer value of the converted string.
     */
    public int string2int( String str ) {
        // hint: use charAt(0) for first char, charAt(1) for next, ...
        // hint: see Character.digit
        int v = 0;
        return v;
    }
 
 
    // code for testing
    public static void printInt2StringDecimal(Convert4Positions conv, int v ) {
        String sv = conv.int2string( v );
        int iv = conv.string2int( sv );
        // %04d converts an integer into a decimal number with 4 postions
        // with zero padding
        System.out.printf("int2string: %04d is %s%n", v, sv );
        System.out.printf("string2int: %s is %04d%n", sv, iv );
    }
 
    public static void printInt2StringOctal(Convert4Positions conv, int v ) {
        String sv = conv.int2string( v );
        int iv = conv.string2int( sv );
        // %04o converts an integer into a octal number with 4 postions
        // with zero padding
        System.out.printf("int2string: %04o is %s%n", v, sv );
        System.out.printf("string2int: %s is %04o%n", sv, iv );
    }
 
    public static void printInt2StringBinary(Convert4Positions conv, String sv ) {
        int iv = conv.string2int( sv );
        String ssv = conv.int2string( iv );
        // there will be no leading zeros
        System.out.printf("int2string: %s is %s%n", sv, Integer.toBinaryString(iv) );
        // I am using the orginal sv
        System.out.printf("int2string: %s is %s%n", sv, ssv );
    }
 
    /**
     * Provide simple console output based testing.
     */
    public static void main( String[] args ) {
        System.out.println("Decimal");
        Convert4Positions decimal = new Convert4Positions( 10 );
        printInt2StringDecimal( decimal, 1234 );
        printInt2StringDecimal( decimal, 9876 );
        printInt2StringDecimal( decimal, 47 );
 
        System.out.println();
        System.out.println("Octal");
        Convert4Positions octal = new Convert4Positions( 8 );
        // In Java, octal numbers start with 0
        printInt2StringOctal( octal, 01234 );
        printInt2StringOctal( octal, 07654 );
        printInt2StringOctal( octal, 034 );
 
        System.out.println();
        System.out.println("Binary");
        Convert4Positions binary = new Convert4Positions( 2 );
        printInt2StringBinary( binary, "0101" );
        printInt2StringBinary( binary, "1001" );
    }
}

Originally Posted by danielp1213

I am pretty sure the int2string and string2int are in the wrong place but correct me if I am wrong.

Being in the worng place is not the issue. The problem is those methods do not do what they are supposed to. All int2String does is return an empty string. All string2int does is return 0. I assume your assignment is to actually complete the code in those methods.

What do you mean by "under"? The location of methods in not important.

public String int2string( int value ) {
        // hint: see Character.forDigit
        String str = "";
        // add code here to finish method
        return str;
    }

See comment above.

You add code that will convert the int to a String, just like the method name says it should do.