Class Conversions

java.lang.Object
uk.ac.starlink.ttools.func.Conversions
public class Conversions extends Object
Functions for converting between strings and numeric values.
Since:
2 Sep 2004
Author:
Mark Taylor (Starlink)

  • Method Summary

    Modifier and Type
    Method
    Description
    static int
    fromHex(String hexVal)
    Converts a string representing a hexadecimal number to its integer value.
    static BigDecimal
    parseBigDecimal(String str)
    Attempts to interpret a string as a "BigDecimal" value.
    static BigInteger
    parseBigInteger(String str)
    Attempts to interpret a string as a "BigInteger" value.
    static byte
    parseByte(String str)
    Attempts to interpret a string as a byte (8-bit signed integer) value.
    static double
    parseDouble(String str)
    Attempts to interpret a string as a double (64-bit signed integer) value.
    static double[]
    parseDoubles(String str)
    Attempts to interpret a string as an array of floating point values.
    static float
    parseFloat(String str)
    Attempts to interpret a string as a float (32-bit floating point) value.
    static int
    parseInt(String str)
    Attempts to interpret a string as an int (32-bit signed integer) value.
    static int[]
    parseInts(String str)
    Attempts to interpret a string as an array of integer values.
    static long
    parseLong(String str)
    Attempts to interpret a string as a long (64-bit signed integer) value.
    static short
    parseShort(String str)
    Attempts to interpret a string as a short (16-bit signed integer) value.
    static byte
    toByte(double value)
    Attempts to convert the numeric argument to a byte (8-bit signed integer) result.
    static double
    toDouble(double value)
    Converts the numeric argument to a double (64-bit signed integer) result.
    static float
    toFloat(double value)
    Attempts to convert the numeric argument to a float (32-bit floating point) result.
    static String
    toHex(long value)
    Converts the integer argument to hexadecimal form.
    static int
    toInteger(double value)
    Attempts to convert the numeric argument to an int (32-bit signed integer) result.
    static long
    toLong(double value)
    Attempts to convert the numeric argument to a long (64-bit signed integer) result.
    static short
    toShort(double value)
    Attempts to convert the numeric argument to a short (16-bit signed integer) result.
    static String
    toString(boolean booleanVal)
    Turns a boolean value into a string.
    static String
    toString(byte byteVal)
    Turns a byte value into a string.
    static String
    toString(char charVal)
    Turns a single character value into a string.
    static String
    toString(double fpVal)
    Turns a numeric value into a string.
    static String
    toString(long intVal)
    Turns an integer numeric value into a string.
    static String
    toString(Object objVal)
    Turns any object value into a string.

    Methods inherited from class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Method Details

    • toString

      public static String toString(double fpVal)
      Turns a numeric value into a string.
      Parameters:
      fpVal - floating point numeric value
      Returns:
      a string representation of fpVal

    • toString

      public static String toString(long intVal)
      Turns an integer numeric value into a string.
      Parameters:
      intVal - integer numeric value
      Returns:
      a string representation of intVal

    • toString

      public static String toString(char charVal)
      Turns a single character value into a string.
      Parameters:
      charVal - character numeric value
      Returns:
      a string representation of charVal

    • toString

      public static String toString(byte byteVal)
      Turns a byte value into a string.
      Parameters:
      byteVal - byte numeric value
      Returns:
      a string representation of byteVal

    • toString

      public static String toString(boolean booleanVal)
      Turns a boolean value into a string.
      Parameters:
      booleanVal - boolean value (true or false)
      Returns:
      a string representation of booleanVal ("true" or "false")

    • toString

      public static String toString(Object objVal)
      Turns any object value into a string. As applied to existing string values this isn't really useful, but it means that you can apply toString to any object value without knowing its type and get a useful return from it.
      Parameters:
      objVal - non-primitive value
      Returns:
      a string representation of objVal

    • parseByte

      public static byte parseByte(String str)
      Attempts to interpret a string as a byte (8-bit signed integer) value. If the input string can't be interpreted in this way, a blank value will result.
      Parameters:
      str - string containing numeric representation
      Returns:
      byte value of str

    • parseShort

      public static short parseShort(String str)
      Attempts to interpret a string as a short (16-bit signed integer) value. If the input string can't be interpreted in this way, a blank value will result.
      Parameters:
      str - string containing numeric representation
      Returns:
      byte value of str

    • parseInt

      public static int parseInt(String str)
      Attempts to interpret a string as an int (32-bit signed integer) value. If the input string can't be interpreted in this way, a blank value will result.
      Parameters:
      str - string containing numeric representation
      Returns:
      byte value of str

    • parseLong

      public static long parseLong(String str)
      Attempts to interpret a string as a long (64-bit signed integer) value. If the input string can't be interpreted in this way, a blank value will result.
      Parameters:
      str - string containing numeric representation
      Returns:
      byte value of str

    • parseFloat

      public static float parseFloat(String str)
      Attempts to interpret a string as a float (32-bit floating point) value. If the input string can't be interpreted in this way, a blank value will result.
      Parameters:
      str - string containing numeric representation
      Returns:
      byte value of str

    • parseDouble

      public static double parseDouble(String str)
      Attempts to interpret a string as a double (64-bit signed integer) value. If the input string can't be interpreted in this way, a blank value will result.
      Parameters:
      str - string containing numeric representation
      Returns:
      byte value of str

    • parseBigInteger

      public static BigInteger parseBigInteger(String str)
      Attempts to interpret a string as a "BigInteger" value. This can be used for working with string representations of integers that can't be stored as an unsigned 64-bit value.

      The result is a BigInteger object, which can't be used in normal numeric expressions, but has a number of methods defined on it for comparison, arithmetic, bit manipulation etc. See the java.math.BigInteger javadocs for details.

      Parameters:
      str - string containing numeric representation
      Returns:
      BigInteger value of str
      Examples:
      parseBigInteger("-20000000000000000023").doubleValue() = -2e19, parseBigInteger("18446744073709551616").testBit(64) = true

    • parseBigDecimal

      public static BigDecimal parseBigDecimal(String str)
      Attempts to interpret a string as a "BigDecimal" value. This can be used for working with string representations of non-integer values that require more precision or range than is possible in a 64-bit IEEE-754 double precision variable.

      The result is a BigDecimal object, which can't be used in normal numeric expressions, but has a number of methods defined on it for comparison, arithmetic, bit manipulation etc. See the java.math.BigDecimal javadocs for details.

      Parameters:
      str - string contining numeric representation
      Returns:
      BigDecimal value of str
      Examples:
      parseBigDecimal("101").compareTo(parseBigDecimal("102")) = -1

    • parseInts

      public static int[] parseInts(String str)
      Attempts to interpret a string as an array of integer values. An ad-hoc algorithm is used that tries to extract a list of integers from a string; a comma- or space-separated list of integer values will work, and other formats may or may not.

      The details of this function's behaviour may change in future releases.

      Parameters:
      str - string containing a list of integer values
      Returns:
      array of integer values
      Examples:
      parseInts("9 8 -23") = [9, 8, -23], parseInts("tiddly-pom") = []

    • parseDoubles

      public static double[] parseDoubles(String str)
      Attempts to interpret a string as an array of floating point values. An ad-hoc algorithm is used that tries to extract a list of numeric values from a string; a comma- or space-separated list of floating point values will work, and other formats may or may not.

      This function can be used as a hacky way to extract the numeric values from an STC-S (for instance ObsCore/EPNcore s_region) string.

      The details of this function's behaviour may change in future releases.

      Parameters:
      str - string containing a list of floating point values
      Returns:
      array of floating point values
      Examples:
      parseDoubles("1.3, 99e1, NaN, -23") = [1.3, 990.0, NaN, -23.0], parseDoubles("Polygon ICRS 0.8 2.1 9.0 2.1 6.2 8.6") = [0.8, 2.1, 9.0, 2.1, 6.2, 8.6], parseDoubles("La la la") = []

    • toByte

      public static byte toByte(double value)
      Attempts to convert the numeric argument to a byte (8-bit signed integer) result. If it is out of range, a blank value will result.
      Parameters:
      value - numeric value for conversion
      Returns:
      value converted to type byte

    • toShort

      public static short toShort(double value)
      Attempts to convert the numeric argument to a short (16-bit signed integer) result. If it is out of range, a blank value will result.
      Parameters:
      value - numeric value for conversion
      Returns:
      value converted to type short

    • toInteger

      public static int toInteger(double value)
      Attempts to convert the numeric argument to an int (32-bit signed integer) result. If it is out of range, a blank value will result.
      Parameters:
      value - numeric value for conversion
      Returns:
      value converted to type int

    • toLong

      public static long toLong(double value)
      Attempts to convert the numeric argument to a long (64-bit signed integer) result. If it is out of range, a blank value will result.
      Parameters:
      value - numeric value for conversion
      Returns:
      value converted to type long

    • toFloat

      public static float toFloat(double value)
      Attempts to convert the numeric argument to a float (32-bit floating point) result. If it is out of range, a blank value will result.
      Parameters:
      value - numeric value for conversion
      Returns:
      value converted to type float

    • toDouble

      public static double toDouble(double value)
      Converts the numeric argument to a double (64-bit signed integer) result.
      Parameters:
      value - numeric value for conversion
      Returns:
      value converted to type double

    • toHex

      public static String toHex(long value)
      Converts the integer argument to hexadecimal form.
      Parameters:
      value - integer value
      Returns:
      hexadecimal representation of value
      Examples:
      toHex(42) = "2a"

    • fromHex

      public static int fromHex(String hexVal)
      Converts a string representing a hexadecimal number to its integer value.
      Parameters:
      hexVal - hexadecimal representation of value
      Returns:
      integer value represented by hexVal
      Examples:
      fromHex("2a") = 42

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