package beginner;

import com.sandwich.koan.Koan;

import java.util.*;

import java.text.MessageFormat;

import static com.sandwich.koan.constant.KoanConstants.*;

import static com.sandwich.util.Assert.*;

public class AboutStrings {

@Koan

public void implicitStrings() {

assertEquals("just a plain ole string".getClass(), __);

}

@Koan

public void newString() {

// very rarely if ever should Strings be created via new String() in

// practice - generally it is redundant, and done repetitively can be slow

String string = new String();

String empty = "";

assertEquals(string.equals(empty), __);

}

@Koan

public void newStringIsRedundant() {

String stringInstance = "zero";

String stringReference = new String(stringInstance);

assertEquals(stringInstance.equals(stringReference), __);

}

@Koan

public void newStringIsNotIdentical() {

String stringInstance = "zero";

String stringReference = new String(stringInstance);

assertEquals(stringInstance == stringReference, __);

}

@Koan

public void stringConcatenation() {

String one = "one";

String space = " ";

String two = "two";

assertEquals(one + space + two, __);

}

@Koan

public void stringBuilderCanActAsAMutableString() {

// StringBuilder concatenation looks uglier, but is useful when you need a

// mutable String like object. It used to be more efficient than using +

// to concatenate numerous strings, however this is optimized in the compiler now.

// Usually + concatenation is more appropriate than StringBuilder.

assertEquals(new StringBuilder("one").append(" ").append("two").toString(), __);

}

@Koan

public void readableStringFormattingWithStringFormat() {

assertEquals(String.format("%s %s %s", "a", "b", "a"), __);

}

@Koan

public void extraArgumentsToStringFormatGetIgnored() {

assertEquals(String.format("%s %s %s", "a", "b", "c", "d"), __);

}

@Koan

public void insufficientArgumentsToStringFormatCausesAnError() {

try {

String.format("%s %s %s", "a", "b");

fail("No Exception was thrown!");

} catch (Exception e) {

assertEquals(e.getClass(), __);

assertEquals(e.getMessage(), __);

}

}

@Koan

public void readableStringFormattingWithMessageFormat() {

assertEquals(MessageFormat.format("{0} {1} {0}", "a", "b"), __);

}

@Koan

public void extraArgumentsToMessageFormatGetIgnored() {

assertEquals(MessageFormat.format("{0} {1} {0}", "a", "b", "c"), __);

}

@Koan

public void insufficientArgumentsToMessageFormatDoesNotReplaceTheToken() {

assertEquals(MessageFormat.format("{0} {1} {0}", "a"), __);

}

}