Addition/Subtraction Operator

Overview

+ and - operators are showing of addition and subtraction operations. Those operators will automatically make it promote to Big Integer when it is over 64 bit integer range.

var a = 10;
var b = a + 1;                  // 10 + 1 => 11
var c = 0x7fffffffffffffff + a; // 0x7fffffffffffffff + 10 => 0x8000000000000009

This can be also used with assignment operator as += or -=.

var a = 0x05;
a += 0x06;          // 5 + 6 => 11

Note that those operators will treat null as 0.

Examples

Example 1. Addition

Code

function test(a, b) {
    return a + b;
}

System.println(test(0x05, 1));
System.println(test(10, -2048));
System.println(test(null, 0x05));
System.println(test(0x07, null));

Result

6
-2038
5
7

Example 2. Subtraction

Code

function test(a, b) {
    return a - b;
}

System.println(test(0x05, 1));
System.println(test(10, -2048));
System.println(test(null, 0x05));
System.println(test(0x07, null));

Result

4
2058
-5
7

Example 3. Big Integer Addition

Code

function test(a, b) {
    return (a + b).toString(16);
}

System.println(test(0x7fffffffffffffff, 2));
System.println(test(0x7fffffffffffffff + 1, -2));

Result

8000000000000001
7ffffffffffffffe

Example 4. Big Integer Subtraction

Code

function test(a, b) {
    return (a - b).toString(16);
}

System.println(test(0x7fffffffffffffff, -2));
System.println(test(0x7fffffffffffffff + 1, 2));

Result

8000000000000001
7ffffffffffffffe