Objects

checkFromIndexSize

static fun checkFromIndexSize(
    fromIndex: Int, 
    size: Int, 
    length: Int
): Int

Checks if the sub-range from fromIndex (inclusive) to fromIndex + size (exclusive) is within the bounds of range from 0 (inclusive) to length (exclusive).

The sub-range is defined to be out of bounds if any of the following inequalities is true:

• fromIndex < 0
• size < 0
• fromIndex + size > length, taking into account integer overflow
• length < 0, which is implied from the former inequalities

checkFromIndexSize

static fun checkFromIndexSize(
    fromIndex: Long, 
    size: Long, 
    length: Long
): Long

Checks if the sub-range from fromIndex (inclusive) to fromIndex + size (exclusive) is within the bounds of range from 0 (inclusive) to length (exclusive).

The sub-range is defined to be out of bounds if any of the following inequalities is true:

• fromIndex < 0
• size < 0
• fromIndex + size > length, taking into account integer overflow
• length < 0, which is implied from the former inequalities

checkFromToIndex

static fun checkFromToIndex(
    fromIndex: Int, 
    toIndex: Int, 
    length: Int
): Int

Checks if the sub-range from fromIndex (inclusive) to toIndex (exclusive) is within the bounds of range from 0 (inclusive) to length (exclusive).

The sub-range is defined to be out of bounds if any of the following inequalities is true:

• fromIndex < 0
• fromIndex > toIndex
• toIndex > length
• length < 0, which is implied from the former inequalities

checkFromToIndex

static fun checkFromToIndex(
    fromIndex: Long, 
    toIndex: Long, 
    length: Long
): Long

Checks if the sub-range from fromIndex (inclusive) to toIndex (exclusive) is within the bounds of range from 0 (inclusive) to length (exclusive).

The sub-range is defined to be out of bounds if any of the following inequalities is true:

• fromIndex < 0
• fromIndex > toIndex
• toIndex > length
• length < 0, which is implied from the former inequalities

checkIndex

static fun checkIndex(
    index: Int, 
    length: Int
): Int

Checks if the index is within the bounds of the range from 0 (inclusive) to length (exclusive).

The index is defined to be out of bounds if any of the following inequalities is true:

• index < 0
• index >= length
• length < 0, which is implied from the former inequalities

checkIndex

static fun checkIndex(
    index: Long, 
    length: Long
): Long

Checks if the index is within the bounds of the range from 0 (inclusive) to length (exclusive).

The index is defined to be out of bounds if any of the following inequalities is true:

• index < 0
• index >= length
• length < 0, which is implied from the former inequalities

compare

static fun <T : Any!> compare(
    a: T, 
    b: T, 
    c: Comparator<in T>
): Int

{@return 0 if the arguments are identical and {@code * c.compare(a, b)} otherwise} Consequently, if both arguments are null 0 is returned.

Note that if one of the arguments is null, a NullPointerException may or may not be thrown depending on what ordering policy, if any, the Comparator chooses to have for null values.

deepEquals

static fun deepEquals(
    a: Any?, 
    b: Any?
): Boolean

{@return {@code true} if the arguments are deeply equal to each other * and {@code false} otherwise} Two null values are deeply equal. If both arguments are arrays, the algorithm in Arrays.deepEquals is used to determine equality. Otherwise, equality is determined by using the equals method of the first argument.

equals

static fun equals(
    a: Any?, 
    b: Any?
): Boolean

{@return {@code true} if the arguments are equal to each other * and {@code false} otherwise} Consequently, if both arguments are null, true is returned. Otherwise, if the first argument is not null, equality is determined by calling the equals method of the first argument with the second argument of this method. Otherwise, false is returned.

hash

static fun hash(vararg values: Any!): Int

{@return a hash code for a sequence of input values} The hash code is generated as if all the input values were placed into an array, and that array were hashed by calling Arrays.hashCode(Object[]).

This method is useful for implementing Object.hashCode() on objects containing multiple fields. For example, if an object that has three fields, x, y, and z, one could write:

@Override public int hashCode() {
      return Objects.hash(x, y, z);
  }
  

hashCode

static fun hashCode(o: Any?): Int

{@return the hash code of a non-{@code null} argument and 0 for * a {@code null} argument}

isNull

static fun isNull(obj: Any?): Boolean

{@return {@code true} if the provided reference is {@code * null}; {@code false} otherwise}

nonNull

static fun nonNull(obj: Any?): Boolean

{@return {@code true} if the provided reference is non-{@code null}; * {@code false} otherwise}

requireNonNull

static fun <T : Any!> requireNonNull(obj: T?): T

Checks that the specified object reference is not null. This method is designed primarily for doing parameter validation in methods and constructors, as demonstrated below:

public Foo(Bar bar) {
      this.bar = Objects.requireNonNull(bar);
  }
  

requireNonNull

static fun <T : Any!> requireNonNull(
    obj: T?, 
    message: String
): T

Checks that the specified object reference is not null and throws a customized NullPointerException if it is. This method is designed primarily for doing parameter validation in methods and constructors with multiple parameters, as demonstrated below:

public Foo(Bar bar, Baz baz) {
      this.bar = Objects.requireNonNull(bar, "bar must not be null");
      this.baz = Objects.requireNonNull(baz, "baz must not be null");
  }
  

requireNonNull

static fun <T : Any!> requireNonNull(
    obj: T?, 
    messageSupplier: Supplier<String!>
): T

Checks that the specified object reference is not null and throws a customized NullPointerException if it is.

Unlike the method requireNonNull(Object,String), this method allows creation of the message to be deferred until after the null check is made. While this may confer a performance advantage in the non-null case, when deciding to call this method care should be taken that the costs of creating the message supplier are less than the cost of just creating the string message directly.

requireNonNullElse

static fun <T : Any!> requireNonNullElse(
    obj: T?, 
    defaultObj: T
): T

{@return the first argument if it is non-{@code null} and * otherwise the second argument if it is non-{@code null}}

requireNonNullElseGet

static fun <T : Any!> requireNonNullElseGet(
    obj: T?, 
    supplier: Supplier<out T>
): T

{@return the first argument if it is non-{@code null} and * otherwise the value from {@code supplier.get()} if it is * non-{@code null}}

toIdentityString

static fun toIdentityString(o: Any): String

{@return a string equivalent to the string returned by {@code * Object.toString} if that method and {@code hashCode} are not * overridden}

toString

static fun toString(o: Any?): String

{@return the result of calling {@code toString} for a * non-{@code null} argument and {@code "null"} for a * {@code null} argument}

toString

static fun toString(
    o: Any?, 
    nullDefault: String
): String

{@return the result of calling {@code toString} on the first * argument if the first argument is not {@code null} and the * second argument otherwise}