0_Wrong.js

var methods = [];

for(var i = 0; i < 10; i++)
{
    methods.push(function() {
        require("system").print(i);
    });
}

for(var k = 0; k < 10; k++)
{
    methods[k]();
}

// prints "10" ten times.

1_Fixed.js

var methods = [];

for(var i = 0; i < 10; i++)
{
    (function(){
        var x = i;
        methods.push(function() {
            require("system").print(x);
        });
    })();
}

for(var k = 0; k < 10; k++)
{
    methods[k]();
}

// prints "0,1,2,3,4,5,6,7,8,9"