I am not finding any solutions. Everywhere show just first and last element of an array.
Suppose, I have an array
[
{ name: "Hero", Id: "hero" },
{ name: "About", Id: "about" },
{ name: "Proccess", Id: "process" },
{ name: "Mission", Id: "mission" },
{ name: "Skill", Id: "skill" },
{ name: "Service", Id: "service" },
{ name: "Work", Id: "work" },
{ name: "Contact", Id: "contact" },
]
Here each object has a Id. Suppose active Id is service. When I active Id is service, then I have to find it previous and next Id (previous skill, next work). Here I have to find just previous and next Object according to active Id. Here Active Id can changed. When Active Id is changed then I have to find the changes previous and next object id.
I think I can clear the question. For mine it difficult. Please help me.
You can use array.findIndex to get the current index, then - and + that to get the previous and next respectively. You'll also want to account for out of bounds indexes. The function I have returns undefined if the index if out of bounds.
const arr = [
{ name: "Hero", Id: "hero" },
{ name: "About", Id: "about" },
{ name: "Proccess", Id: "process" },
{ name: "Mission", Id: "mission" },
{ name: "Skill", Id: "skill" },
{ name: "Service", Id: "service" },
{ name: "Work", Id: "work" },
{ name: "Contact", Id: "contact" },
]
const getPrevAndNext = (activeID) => {
const index = arr.findIndex((a) => a.Id === activeID)
if (index === -1) {
return undefined
}
const prev = arr[index - 1]
if (!prev) {
return undefined
}
const next = arr[index + 1]
if (!next) {
return undefined
}
return [prev, next]
}
console.log(getPrevAndNext('service'))You can use old fashioned for loop to iterate over array and check if if Id matches then take the current index and add -1 to get prev and add +1 to get next. As shown in below snippet.
let array = [
{ name: "Hero", Id: "hero" },
{ name: "About", Id: "about" },
{ name: "Proccess", Id: "process" },
{ name: "Mission", Id: "mission" },
{ name: "Skill", Id: "skill" },
{ name: "Service", Id: "service" },
{ name: "Work", Id: "work" },
{ name: "Contact", Id: "contact" },
];
for(let i = 0; i < array.length; i++){
if(array[i].Id === 'service'){
console.log('prev = ' + array[i-1].Id + ' next = ' + array[i+1].Id);
}
}