Integer

Overview

Integer objects are numbers like 1. You can write it in decimal, octal, and hexadecimal numbers.

Methods

There is a special object named as Integer. The methods of Integer can be used for integer values directly.

Method	Meaning
Integer.times(val, callback)	As the range of i = 0 to (val-1), if callback exists, it is the result of callback(i), and if it does not exist, creates an array with i and returns it.
Integer.upto(val, max, callback)	Call callback(i) as an argument in the range of i = val to max.
Integer.downto(val, min, callback)	Call callback(i) as an argument in the range of i = min to val.
Integer.toString(val, base)	Converts val into a string. base only supports 10 and 16.
Integer.toDouble(val)	Converts val into Double.

The Integer object can hold any methods you want to add. For example, see below.

Integer.times100 = function(value) {
    return value * 100;
};
var val = 100.times100();
System.println(val);

Let’s run it.

10000

The receiver comes in the first argument.

Math Object Method

Integer objects have the same special methods as Math objects. See below for details. When written in a concrete example, the following can be written, for example.

var a = 2.pow(10); // same as Math.pow(2, 10) => 1024
var b = (-10).abs(); // same as Math.abs(-10) => 10

Note that unary minus (-) has lower precedence than function calls, so it must be enclosed in parentheses.

Special operator

Unary * operator

When the unary * operator is applied to an integer value, the character string (1 character) corresponding to the character code is returned.

var a = *97; // => "a"

By the way, the reverse conversion (*a) cannot be restored. Note that the unary * operator for strings is an array, so *a in the above example would be an array [97]. To get the character code alone, use a[0].

BigInteger

Converting between Integer and BigInteger will be automatically done. Integer will be dealt with between INT64_MIN and INT64_MAX, and when it is over those range, a value will be converted to BigInteger.

Examples

Example 1. Normal case

Code

System.println(100);
System.println(0xff);
System.println(010);

Result

100
255
8

Example 2. Math

Code

var a = 2.pow(10);
var b = (-10).abs();
System.println(a);
System.println(b);

Result

1024
10

Example 3. BigInteger (1)

Code

var a = 0x7fffffffffffffff - 4;
for (var i = 0; i < 8; ++i) {
    var isI = a.isInteger;
    var isB = a.isBigInteger;
    System.println(a++, ": ", isI ? "Integer, " : "         ", isB ? "BigInteger" : "");
}

Result

9223372036854775803: Integer,
9223372036854775804: Integer,
9223372036854775805: Integer,
9223372036854775806: Integer,
9223372036854775807: Integer,
9223372036854775808: Integer, BigInteger
9223372036854775809: Integer, BigInteger
9223372036854775810: Integer, BigInteger

Example 4. BigInteger (2)

Code

var a = -(0x7fffffffffffffff) - 4;
for (var i = 0; i < 8; ++i) {
    var isI = a.isInteger;
    var isB = a.isBigInteger;
    System.println(a++, ": ", isI ? "Integer, " : "         ", isB ? "BigInteger" : "");
}

Result

-9223372036854775811: Integer, BigInteger
-9223372036854775810: Integer, BigInteger
-9223372036854775809: Integer, BigInteger
-9223372036854775808: Integer,
-9223372036854775807: Integer,
-9223372036854775806: Integer,
-9223372036854775805: Integer,
-9223372036854775804: Integer,