I've been wanting to generate random numbers through a function and then use setInterval to repeat that function and give me a new number every time.
function randNum(prevNum) {
let randNum = Math.round(Math.random() * 12) //choose a number between 0 and 12
while (randNum == prevNum){ //if the chosen number is the same as prevNum, choose another random number
randColor = Math.round(Math.random() * 12)
}
prevNum = randColor //assign current value to parameter
return (prevNum); //return parameter
}
prevNum = 0,
prevNum = setInterval (randNum, 1000, prevNum) //assign returned parameter to current variable, then go back into the function with the new parameter value.
also using node so semicolons might be missing.
When you use prevNum as a setInterval() argument, you're always passing the original value of the variable to the callback function. You should just use the global variable directly rather than passing it as a parameter.
You also have a typo, randColor should be randNum.
let prevNum = 0;
function randNum() {
let newNum
while (true) {
newNum = Math.round(Math.random() * 12) //choose a number between 0 and 12
if (newNum != prevNum) {
break;
}
}
prevNum = newNum //save the current value
console.log(prevNum);
}
let interval = setInterval(randNum, 1000)The return value of the callback function isn't used, so there's no point in return prevNum;. And you shouldn't assign the result of setInterval() to your number variable -- it returns a timer ID, not the value of the function.
You could create a function that returns an iterator and keeps the state:
function randiter(n) {
let num = 0;
const iter = () => {
let cur;
do {
cur = Math.round(Math.random() * n);
} while (cur === num);
num = cur;
return num;
};
return iter;
}
The above version takes the max number as a parameter. Use it like so:
const p12 = randiter(12);
for (let i=0; i<20; i++) {
console.log(p12());
}
or
setInterval(() => console.log(p12()), 1000);
I am the 3%
(and I miss Pascal)
let intervalRef = setInterval( ( prev ) =>
{
let newNum;
do newNum = Math.round(Math.random() * 12)
while( newNum === prev.val )
prev.val = newNum
console.log( newNum )
}
, 1000, { val: null } )
setTimeout(()=>clearInterval(intervalRef), 20000)