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BAEL-1250 Initializing Arrays in Java

This commit is contained in:
Ahmed Tawila 2017-10-23 10:58:07 +02:00
parent 7120a2f1e3
commit d14411e2b4
2 changed files with 47 additions and 1 deletions
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26
core-java/src/main/java/com/baeldung/array/ArrayInitializer.java
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@ -45,4 +45,30 @@ public class ArrayInitializer {
Arrays.fill(array, 0, 3, -50); Arrays.fill(array, 0, 3, -50);
return array; return array;
} }
public static int[] initializeArrayUsingArraysCopy() {
int array[] = { 1, 2, 3, 4, 5 };
int[] copy = Arrays.copyOf(array, 5);
return copy;
}
public static int[] initializeLargerArrayUsingArraysCopy() {
int array[] = { 1, 2, 3, 4, 5 };
int[] copy = Arrays.copyOf(array, 6);
return copy;
}
public static int[] initializeArrayUsingArraysSetAll() {
int[] array = new int[20];
for (int i = 0; i < 20; i++) {
Arrays.setAll(array, p -> {
if (p > 9)
return 0;
else
return p;
});
}
return array;
}
} }

22
core-java/src/test/java/com/baeldung/array/ArrayInitializerTest.java
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@ -5,7 +5,10 @@ import static com.baeldung.array.ArrayInitializer.initializeArrayAtTimeOfDeclara
import static com.baeldung.array.ArrayInitializer.initializeArrayAtTimeOfDeclarationMethod3; import static com.baeldung.array.ArrayInitializer.initializeArrayAtTimeOfDeclarationMethod3;
import static com.baeldung.array.ArrayInitializer.initializeArrayInLoop; import static com.baeldung.array.ArrayInitializer.initializeArrayInLoop;
import static com.baeldung.array.ArrayInitializer.initializeArrayRangeUsingArraysFill; import static com.baeldung.array.ArrayInitializer.initializeArrayRangeUsingArraysFill;
import static com.baeldung.array.ArrayInitializer.initializeArrayUsingArraysCopy;
import static com.baeldung.array.ArrayInitializer.initializeArrayUsingArraysFill; import static com.baeldung.array.ArrayInitializer.initializeArrayUsingArraysFill;
import static com.baeldung.array.ArrayInitializer.initializeArrayUsingArraysSetAll;
import static com.baeldung.array.ArrayInitializer.initializeLargerArrayUsingArraysCopy;
import static com.baeldung.array.ArrayInitializer.initializeMultiDimensionalArrayInLoop; import static com.baeldung.array.ArrayInitializer.initializeMultiDimensionalArrayInLoop;
import static org.junit.Assert.assertArrayEquals; import static org.junit.Assert.assertArrayEquals;
@ -38,11 +41,28 @@ public class ArrayInitializerTest {
assertArrayEquals(new int[] { 1, 2, 3, 4, 5 }, initializeArrayAtTimeOfDeclarationMethod3()); assertArrayEquals(new int[] { 1, 2, 3, 4, 5 }, initializeArrayAtTimeOfDeclarationMethod3());
} }
@Test
public void whenInitializeArrayUsingArraysFill_thenCorrect() { public void whenInitializeArrayUsingArraysFill_thenCorrect() {
assertArrayEquals(new long[] { 30, 30, 30, 30, 30 }, initializeArrayUsingArraysFill()); assertArrayEquals(new long[] { 30, 30, 30, 30, 30 }, initializeArrayUsingArraysFill());
} }
public void whenInitializeArrayRangeUsingArraysFill() { @Test
public void whenInitializeArrayRangeUsingArraysFill_thenCorrect() {
assertArrayEquals(new int[] { -50, -50, -50, 0, 0 }, initializeArrayRangeUsingArraysFill()); assertArrayEquals(new int[] { -50, -50, -50, 0, 0 }, initializeArrayRangeUsingArraysFill());
} }
@Test
public void whenInitializeArrayRangeUsingArraysCopy_thenCorrect() {
assertArrayEquals(new int[] { 1, 2, 3, 4, 5 }, initializeArrayUsingArraysCopy());
}
@Test
public void whenInitializeLargerArrayRangeUsingArraysCopy_thenCorrect() {
assertArrayEquals(new int[] { 1, 2, 3, 4, 5, 0 }, initializeLargerArrayUsingArraysCopy());
}
@Test
public void whenInitializeLargerArrayRangeUsingArraysSetAll_thenCorrect() {
assertArrayEquals(new int[] { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }, initializeArrayUsingArraysSetAll());
}
} }