Ruby: Change negative number to positive number?

What's the simplest way of changing a negative number to positive with ruby?

ie. Change "-300" to "3开发者_StackOverflow中文版00"

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Using abs will return the absolute value of a number

-300.abs  # 300
300.abs   # 300

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Put a negative sign in front of it.

>> --300
=> 300
>> x = -300
=> -300
>> -x
=> 300

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Wouldn't it just be easier to multiply it by negative one?

x * -1

That way you can go back and forth.

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Most programming languages have the ABS method, however there are some that do not Whilst I have not used Ruby before, I am familiar its a framework that runs on PHP

The abs method is available on PHP https://www.php.net/manual/en/function.abs.php

With Ruby the syntax appears slightly different is integer.abs https://www.geeksforgeeks.org/ruby-integer-abs-function-with-example/

But for future reference the abs method is really small to code your self.

here is how in a few different languages:

JavaScript:

function my_abs(integer){
    if (integer < 0){
        return integer * -1;
    }
    return interger;
}

Python:

    def my_abs(integer):
    if (integer < 0):
        return integer * -1
    return integer

c:

int my_abs(int integer){
    if (interger < 0){
        return integer * -1;
    }
    return integer;
}

This means should you ever find yourself with a programming language that doesnt have a built in abs method, you know how to code your own its just simply multiply any negative number by -1 as you would of gathered in my examples