I'm trying to find a solution to make a loop (Javascript) until the array of object is empty. Here the object that I want to use :
"chain": {
"evolves_to": [{
"evolves_to": [{
"evolves_to": [],
"species": {
"name": "nidoqueen"
}
}],
"species": {
"name": "nidorina"
}
}],
"species": {
"name": "nidoran-f"
}
}
I would like to loop until to find the variable evolves_to empty. and in each loop using the species.name, to list the evolution, in my case :
nidoran-f -> nidorina -> nidoqueen
I can not find yet a good way to do it. A bit lost. Thank you for your help ;)
You can use a recursive function:
const chain = {
"evolves_to": [{
"evolves_to": [{
"evolves_to": [],
"species": {
"name": "nidoqueen"
}
}],
"species": {
"name": "nidorina"
}
}],
"species": {
"name": "nidoran-f"
}
}
, traverse = obj => {
if(!obj.evolves_to.length) {
console.log(obj.species.name)
return
} else {
console.log(obj.species.name, "=>")
traverse(obj.evolves_to[0])
}
}
traverse(chain)Or to collect values in an array:
const chain = {
"evolves_to": [{
"evolves_to": [{
"evolves_to": [],
"species": {
"name": "nidoqueen"
}
}],
"species": {
"name": "nidorina"
}
}],
"species": {
"name": "nidoran-f"
}
}
, arr = []
, traverse = obj => {
if(!obj.evolves_to.length) {
arr.push(obj.species.name)
return
} else {
arr.push(obj.species.name)
traverse(obj.evolves_to[0])
}
}
traverse(chain)
console.log(arr.join(" -> "))A simple recursive function should do the trick:
const evolutions = {
"chain": {
"evolves_to": [{
"evolves_to": [{
"evolves_to": [],
"species": {
"name": "nidoqueen"
}
}],
"species": {
"name": "nidorina"
}
}],
"species": {
"name": "nidoran-f"
}
}
}
function findNoEvolution(obj, evolutionStages) {
if (obj.evolves_to.length > 0) {
for (let i = 0; i < obj.evolves_to.length; i += 1) {
const found = findNoEvolution(obj.evolves_to[i], evolutionStages);
if (found) {
evolutionStages.push(obj.species.name)
return found;
}
}
}
evolutionStages.push(obj.species.name)
return true;
}
const evolutionStages = [];
findNoEvolution(evolutions.chain, evolutionStages);
const evolutionStagesStr = evolutionStages.reverse().join(' -> ');
console.log(evolutionStagesStr);
The result evolution array is then reversed to begin from the 1st evolution via reverse() and joined by arrows via joing(' -> ').