Comparison by Equation

Overview

Operators for equation are == and !=.

var a = 0x05;
var b = a == 0x06;   // 5 == 6 => false means 0

If the type is different, it will be compared after converting by the table below.

	Inteer	Double	String
Integer	Integer	Double	String by dec
Double	Double	Double	-
String	String by dec	-	String

Comparing between Integer and String is done as stringified by decimal numbers.

Examples

Example 1. Use == for Integers

Code

function test(label, func, a, b) {
    return ":: %8d %s %8d => %d" % a % label % b % func(a, b);
}

System.println(test("==", &(a, b) => a == b, 0x05, 0x06));
System.println(test("==", &(a, b) => a == b, 99, 99));
System.println(test("==", &(a, b) => a == b, 100, 11));
System.println(test("==", &(a, b) => a == b, null, 0x05));
System.println(test("==", &(a, b) => a == b, 0x07, null));

Result

::        5 ==        6 => 0
::       99 ==       99 => 1
::      100 ==       11 => 0
:: ((null)) ==        5 => 0
::        7 == ((null)) => 0

Example 2. Use == between Integer and Double

Code

function test(label, func, a, b) {
    return ":: %8d %s %8d => %d" % a % label % b % func(a, b);
}

System.println(test("==", &(a, b) => a == b, 1, 1.0));

Result

::        1 ==        1 => 1

Example 3. Use == between Integer and String

Code

function test(label, func, a, b) {
    return ":: %8d %s %8d => %d" % a % label % b % func(a, b);
}

System.println(test("==", &(a, b) => a == b, 0xff, "255"));
System.println(test("==", &(a, b) => a == b, 0xff, "ff"));

Result

::      255 ==      255 => 1
::      255 ==       ff => 0

Example 4. Use == between String and Integer

Code

function test(label, func, a, b) {
    return ":: %8d %s %8d => %d" % a % label % b % func(a, b);
}

System.println(test("==", &(a, b) => a == b, "255", 0xff));
System.println(test("==", &(a, b) => a == b, "ff", 0xff));

Result

::      255 ==      255 => 1
::       ff ==      255 => 0

Example 5. Use != for Integers

Code

function test(label, func, a, b) {
    return ":: %8d %s %8d => %d" % a % label % b % func(a, b);
}

System.println(test("!=", &(a, b) => a != b, 0x05, 0x06));
System.println(test("!=", &(a, b) => a != b, 99, 99));
System.println(test("!=", &(a, b) => a != b, 100, 11));
System.println(test("!=", &(a, b) => a != b, null, 0x05));
System.println(test("!=", &(a, b) => a != b, 0x07, null));

Result

::        5 !=        6 => 1
::       99 !=       99 => 0
::      100 !=       11 => 1
:: ((null)) !=        5 => 1
::        7 != ((null)) => 1

Example 6. Use != between Integer and Double

Code

function test(label, func, a, b) {
    return ":: %8d %s %8d => %d" % a % label % b % func(a, b);
}

System.println(test("!=", &(a, b) => a != b, 1, 1.0));

Result

::        1 !=        1 => 0

Example 7. Use != between Integer and String

Code

function test(label, func, a, b) {
    return ":: %8d %s %8d => %d" % a % label % b % func(a, b);
}

System.println(test("!=", &(a, b) => a != b, 0xff, "255"));
System.println(test("!=", &(a, b) => a != b, 0xff, "ff"));

Result

::      255 !=      255 => 0
::      255 !=       ff => 1

Example 8. Use != between String and Integer

Code

function test(label, func, a, b) {
    return ":: %8d %s %8d => %d" % a % label % b % func(a, b);
}

System.println(test("!=", &(a, b) => a != b, "255", 0xff));
System.println(test("!=", &(a, b) => a != b, "ff", 0xff));

Result

::      255 !=      255 => 0
::       ff !=      255 => 1