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Is this correct?

Is this correct?

Is this correct?

According to page 26 in this PDF tutorial from Tutorials Point, it says the result would be "true", but is actually giving "false".
It goes like this:

Assume variable A holds 10 and variable B holds 20, then:

1. && (Logical AND)
If both the operands are non-zero, then the condition becomes true.
Ex: (A && B) is true.

Along the lines above, also in the same page, the one below is not giving what they said it would.

! (Logical NOT)
Reverses the logical state of its operand. If a condition is true, then the Logical NOT operator will make it false.
Ex: ! (A && B) is false.

document.write("!(a && b) => ");
result = (!(a && b));

But it's giving me TRUE.

Also this one is not giving the expected result, in page 21:

var a = 10;
var b = 20;
var c = "Test";
var linebreak = "<br />";
a = a++;
document.write("a++ = ");
result = a++;
b = b--;
document.write("b-- = ");
result = b--;

RE: Is this correct?

The first comparison is correctly returning false for me. Make sure both a and b are defined before you do the comparison.

As to the ++ issue. That's has always been confusing. The gist of it, is that a=a++, will assign the value of a before it increments a by 1.
Basically a++ returns a which is assigned to a. And then it adds 1 to a.

A better explanation here(though it may still not make sense):
Difference betwen a++ and ++a
You can perform the addition directly without assigning it, and the variable will be updated.


//no assignment. 

Your other option is to change the order:



This will ad 1 to a first, and then assign the resulting value back to a.

Phil AKA Vacunita
OS-ception: Running Linux on a Virtual Machine in Windows which itself is running in a Virtual Machine on Mac OSx.

Web & Tech

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