What does it mean when you put Loop = 1; in a program

this is just a random question but i noticed on a while loop program i was reading written by someone else that they defined

loop = 1

then when they began the while loop they started it off as while (loop). what does this do to a while loop? i usually see some condition being evaluated for while before a condition statement is presented but here im not familiar with why the while loop was used this way. this is an example of what im looking at:

loop = 1; 
%initialize loop
while(loop) 
    statement
    statement

Answer 1

[David Hill]

while 1%continuous loop until broken from within
    if
        break;
    end
end

[Reila01]

thank you!

Answer 2

[James Tursa]

This is a "forever" loop. It executes until a break statement is encountered. E.g., the general construct is

while( 1 )
    % stuff
    if( some condition is met )
        break;
    end
end

[Reila01]

okay that makes sense thank you!

[Walter Roberson]

However, it is possible that the code changes the variable named loop in order to break out of the loop.

The general form is

while condition
    some code
    if some condition
        break
    end
    some more code
end

where the "if" and "some more code" might not be present.

A condition in MATLAB is anything that can be evaluated to be 0 or non-zero (and non-nan). That does not have to be a relational expression: it can be a simple variable:

need_a_valid_answer = true;
while need_a_valid_answer
    how_much = input('How much to withdraw?');
    if isnumeric(howmuch) && isscalar(howmuch) && howmuch >= 0
        need_a_valid_answer = false;
    end
end

To which you would add the knowledge that any non-zero value can be used instead of true:

remaining_tries = 5;
while remaining_tries      %implicitly this is remaining_tries ~= 0
    how_much = input('How much to withdraw?');
    if isnumeric(howmuch) && isscalar(howmuch) && howmuch >= 0
        remaining_tries = 0;
    else
        remaining_tries = remaining_tries - 1;
    end
end