@CheckReturnValue @GwtCompatible(emulated=true) public final class Floats extends Object
Static utility methods pertaining to float primitives, that are not already found in either Float or Arrays.
See the Guava User Guide article on primitive utilities.
| Modifier and Type | Field and Description |
|---|---|
static int |
BYTES
The number of bytes required to represent a primitive
float value. |
| Modifier and Type | Method and Description |
|---|---|
static List<Float> |
asList(float... backingArray)
Returns a fixed-size list backed by the specified array, similar to
Arrays.asList(Object[]). |
static int |
compare(float a,
float b)
Compares the two specified
float values using Float.compare(float, float). |
static float[] |
concat(float[]... arrays)
Returns the values from each provided array combined into a single array.
|
static boolean |
contains(float[] array,
float target)
Returns
true if target is present as an element anywhere in array. |
static float[] |
ensureCapacity(float[] array,
int minLength,
int padding)
Returns an array containing the same values as
array, but guaranteed to be of a specified minimum length. |
static int |
hashCode(float value)
Returns a hash code for
value; equal to the result of invoking ((Float) value).hashCode(). |
static int |
indexOf(float[] array,
float target)
Returns the index of the first appearance of the value
target in array. |
static int |
indexOf(float[] array,
float[] target)
Returns the start position of the first occurrence of the specified
target within array, or -1 if there is no such occurrence. |
static boolean |
isFinite(float value)
Returns
true if value represents a real number. |
static String |
join(String separator,
float... array)
Returns a string containing the supplied
float values, converted to strings as specified by Float.toString(float), and separated by separator. |
static int |
lastIndexOf(float[] array,
float target)
Returns the index of the last appearance of the value
target in array. |
static Comparator<float[]> |
lexicographicalComparator()
Returns a comparator that compares two
float arrays lexicographically. |
static float |
max(float... array)
Returns the greatest value present in
array, using the same rules of comparison as Math.max(float, float). |
static float |
min(float... array)
Returns the least value present in
array, using the same rules of comparison as Math.min(float, float). |
static Converter<String,Float> |
stringConverter()
Returns a serializable converter object that converts between strings and floats using
Float.valueOf(java.lang.String) and Float.toString(). |
static float[] |
toArray(Collection<? extends Number> collection)
Returns an array containing each value of
collection, converted to a float value in the manner of Number.floatValue(). |
static Float |
tryParse(String string)
Parses the specified string as a single-precision floating point value.
|
public static final int BYTES
The number of bytes required to represent a primitive float value.
public static int hashCode(float value)
Returns a hash code for value; equal to the result of invoking ((Float) value).hashCode().
value - a primitive float valuepublic static int compare(float a,
float b)
Compares the two specified float values using Float.compare(float, float). You may prefer to invoke that method directly; this method exists only for consistency with the other utilities in this package.
Note: this method simply delegates to the JDK method Float.compare(float, float). It is provided for consistency with the other primitive types, whose compare methods were not added to the JDK until JDK 7.
a - the first float to compareb - the second float to compareFloat.compare(float, float)public static boolean isFinite(float value)
Returns true if value represents a real number. This is equivalent to, but not necessarily implemented as, !(Float.isInfinite(value) || Float.isNaN(value)).
public static boolean contains(float[] array,
float target)
Returns true if target is present as an element anywhere in array. Note that this always returns false when target is NaN.
array - an array of float values, possibly emptytarget - a primitive float valuetrue if array[i] == target for some value of ipublic static int indexOf(float[] array,
float target)
Returns the index of the first appearance of the value target in array. Note that this always returns -1 when target is NaN.
array - an array of float values, possibly emptytarget - a primitive float valuei for which array[i] == target, or -1 if no such index exists.public static int indexOf(float[] array,
float[] target)
Returns the start position of the first occurrence of the specified target within array, or -1 if there is no such occurrence.
More formally, returns the lowest index i such that java.util.Arrays.copyOfRange(array, i, i + target.length) contains exactly the same elements as target.
Note that this always returns -1 when target contains NaN.
array - the array to search for the sequence targettarget - the array to search for as a sub-sequence of arraypublic static int lastIndexOf(float[] array,
float target)
Returns the index of the last appearance of the value target in array. Note that this always returns -1 when target is NaN.
array - an array of float values, possibly emptytarget - a primitive float valuei for which array[i] == target, or -1 if no such index exists.public static float min(float... array)
Returns the least value present in array, using the same rules of comparison as Math.min(float, float).
array - a nonempty array of float valuesarray that is less than or equal to every other value in the arrayIllegalArgumentException - if array is emptypublic static float max(float... array)
Returns the greatest value present in array, using the same rules of comparison as Math.max(float, float).
array - a nonempty array of float valuesarray that is greater than or equal to every other value in the arrayIllegalArgumentException - if array is emptypublic static float[] concat(float[]... arrays)
Returns the values from each provided array combined into a single array. For example, concat(new float[] {a, b}, new float[] {}, new float[] {c} returns the array {a, b, c}.
arrays - zero or more float arrays@Beta public static Converter<String,Float> stringConverter()
Returns a serializable converter object that converts between strings and floats using Float.valueOf(java.lang.String) and Float.toString().
public static float[] ensureCapacity(float[] array,
int minLength,
int padding)
Returns an array containing the same values as array, but guaranteed to be of a specified minimum length. If array already has a length of at least minLength, it is returned directly. Otherwise, a new array of size minLength + padding is returned, containing the values of array, and zeroes in the remaining places.
array - the source arrayminLength - the minimum length the returned array must guaranteepadding - an extra amount to “grow” the array by if growth is necessaryarray, with guaranteed minimum length minLengthIllegalArgumentException - if minLength or padding is negativepublic static String join(String separator, float... array)
Returns a string containing the supplied float values, converted to strings as specified by Float.toString(float), and separated by separator. For example, join("-", 1.0f, 2.0f, 3.0f) returns the string "1.0-2.0-3.0".
Note that Float.toString(float) formats float differently in GWT. In the previous example, it returns the string "1-2-3".
separator - the text that should appear between consecutive values in the resulting string (but not at the start or end)array - an array of float values, possibly emptypublic static Comparator<float[]> lexicographicalComparator()
Returns a comparator that compares two float arrays lexicographically. That is, it compares, using compare(float, float)), the first pair of values that follow any common prefix, or when one array is a prefix of the other, treats the shorter array as the lesser. For example, [] < [1.0f] < [1.0f, 2.0f]
< [2.0f].
The returned comparator is inconsistent with Object.equals(Object) (since arrays support only identity equality), but it is consistent with Arrays.equals(float[], float[]).
public static float[] toArray(Collection<? extends Number> collection)
Returns an array containing each value of collection, converted to a float value in the manner of Number.floatValue().
Elements are copied from the argument collection as if by collection.toArray(). Calling this method is as thread-safe as calling that method.
collection - a collection of Number instancescollection, in the same order, converted to primitivesNullPointerException - if collection or any of its elements is nullCollection<Float> before 12.0)public static List<Float> asList(float... backingArray)
Returns a fixed-size list backed by the specified array, similar to Arrays.asList(Object[]). The list supports List.set(int, Object), but any attempt to set a value to null will result in a NullPointerException.
The returned list maintains the values, but not the identities, of Float objects written to or read from it. For example, whether list.get(0) == list.get(0) is true for the returned list is unspecified.
The returned list may have unexpected behavior if it contains NaN, or if NaN is used as a parameter to any of its methods.
backingArray - the array to back the list@Beta @Nullable @CheckForNull @GwtIncompatible(value="regular expressions") public static Float tryParse(String string)
Parses the specified string as a single-precision floating point value. The ASCII character '-' (‘\u002D’) is recognized as the minus sign.
Unlike Float.parseFloat(String), this method returns null instead of throwing an exception if parsing fails. Valid inputs are exactly those accepted by Float.valueOf(String), except that leading and trailing whitespace is not permitted.
This implementation is likely to be faster than Float.parseFloat if many failures are expected.
string - the string representation of a float valuestring, or null if string has a length of zero or cannot be parsed as a float value