How can I make a script in jquery to increase an index by a certain number and then decrease one by one to zero.
I'm doing the following to increase but I'd like it to drop to zero by the time it gets to # 5.
var index = 0;
setInterval(function ()
{
teste();
}, 10000, true );
function teste()
{
index++;
}
You need a control variable indicating whether it is to increment or decrement, or use some modular arithmetic:
Using a control variable:
var index = 0;
var inc = +1;
var handle = setInterval(teste, 10000, true); // como o @bfavaretto indicou!
function teste()
{
if (index == 5)
inc = -1;
index += inc;
if (index == 0)
clearInterval(handle);
}
Here's another idea, using an object to store the value of the index and also the direction; because I did not see the question in time and without deference to the reply from Miguel Angelo that was already accepted when I placed mine .
var index = { // um objeto para guardar ...
valor: 0, // o valor inicial e que vai mudar
direcao: , // a direccao, se sobe (1) ou desce (0)
maximo: 5 // o máximo que pode atingir
};
var contador = setInterval(teste, 10000);
function teste() {
// usar o valor
console.log(index.valor);
index.direcao ? index.valor++ : index.valor--;
if(index.valor == index.maximo) index.direcao = !index.direcao;
if (!index.direcao && index.valor < 0) clearInterval(contador);
}