在一行中按条件将项目推送到数组

Question

I want something like this and I would like to know if this is possible in JavaScript in one line, or I have to write an if statement

// these versions adds fasle to the array if condition = false let arr = await getArray(params).push(condition && itemToAdd); arr = await getArray(params).push((() => condition && itemToAdd)()); // this version adds undefined to the array if condition = false arr = await getArray(params).push((() => { if (condition) return itemToAdd })());

(the reason I included the getArray part is cuz that's how it looks in my code and I don't actually save this array to a var arr only its being returned right away to its calling function, so that's why I don't want to add a line for the if statement...)

Answer 1

Not sure why you want to do it in a single line, but this can work

let arr = [...await getArray(), itemToAdd].slice(0, condition? undefined: -1);

Here we are pushing the itemToAdd in the array regardless of the condition, but we remove the last element ( itemToAdd ) if the condition is false.

Answer 2

if you are working with reactjs then you can use useState for conditions

const [isCondition, setisCondition] = useState(false);

//but you need if/else to change useState

 if(this_happens) {

setisCondition(true) } else { setisCondition(false) }

//you can do it as like

let arr = await getArray(params).push(isCondition && itemToAdd);