I have a piece of code here, and i wanted to identify the last element paragraph 3 and add some text like - last item and the output would be paragraph 3 - last item.
I would prefer if its recursive since there is no limit on the number children in an object.
obj = {
content: [
{ text: "paragraph 1" },
{
content: [
{ text: "paragraph 2" },
]
},
{ text: "paragraph 3" },
]
}
Another example would be this, its output should be paragraph 5 - last item
obj = {
content: [
{ text: "paragraph 1" },
{
content: [
{ text: "paragraph 2" }
]
},
{ text: "paragraph 3" },
{
content: [
{ text: "paragraph 4" },
{
content: [
{ text: "paragraph 5" }
]
}
]
}
]
}
A simple implementation. Checks the key name and if it's content, it'll recall itself with the last element. Else, it'll return it.
const obj1 = {
content: [{
text: "paragraph 1"
}, {
content: [{
text: "paragraph 2"
}]
}, {
text: "paragraph 3"
}]
};
const obj2 = {
content: [{
text: "paragraph 1"
},
{
content: [{
text: "paragraph 2"
}]
}, {
text: "paragraph 3"
},
{
content: [{
text: "paragraph 4"
},
{
content: [{
text: "paragraph 5"
}]
}
]
}
]
}
function getLatestParagraph(obj) {
for (const key in obj) {
if (key === "content") return getLatestParagraph(obj[key].pop());
return obj[key];
}
}
console.log(getLatestParagraph(obj1))
console.log(getLatestParagraph(obj2))One way is to loop and get a reference to text in one variable and update it each loop. After all the loops end the variable will be pointing to tha last text so you just add ' - last item' to it.
Here is a working example:
const obj1 = {
content: [{
text: 'paragraph 1'
},
{
content: [{
text: 'paragraph 2'
}]
},
{
text: 'paragraph 3'
},
{
content: [{
text: 'paragraph 4'
},
{
content: [{
text: 'paragraph 5'
}]
},
],
},
],
}
const obj2 = {
content: [{
text: 'paragraph 1'
},
{
content: [{
text: 'paragraph 2'
}]
},
{
text: 'paragraph 3'
},
],
}
let last
function getLast(o) {
for (let key in o) {
if (o[key] instanceof Array) {
for (let value of o[key]) {
getLast(value)
}
} else if (key == 'text') {
last = o
}
}
}
getLast(obj1)
last.text += ' - last item'
getLast(obj2)
last.text += ' - last item'
console.log('\nobj1 = ', JSON.stringify(obj1, null, 1))
console.log('\nobj2 = ', JSON.stringify(obj2, null, 1))Edit: If what you actually wanted is just get the text of the last item then you can also do this:
const obj1 = {
content: [{
text: 'paragraph 1'
},
{
content: [{
text: 'paragraph 2'
}]
},
{
text: 'paragraph 3'
},
{
content: [{
text: 'paragraph 4'
},
{
content: [{
text: 'paragraph 5'
}]
},
],
},
],
}
const obj2 = {
content: [{
text: 'paragraph 1'
},
{
content: [{
text: 'paragraph 2'
}]
},
{
text: 'paragraph 3'
},
],
}
let last
function getLast(o) {
for (let key in o) {
if (o[key] instanceof Array) {
for (let value of o[key]) {
getLast(value)
}
} else if (key == 'text') {
last = o
}
}
return last.text
}
const last1 = getLast(obj1)
console.log(last1)
const last2 = getLast(obj2)
console.log(last2)You can map on the content property and return each element. If the content property exists, same condition will run again, else it will print the text property.
let lastItem = {};
function recursive(node) {
if (node.content) {
node.content.map(element => recursive(element));
} else if (node.text) {
lastItem = node.text;
}
}
obj.content.map(node => recursive(node));
console.log(lastItem + " - last item");
Working demo: https://jsfiddle.net/4f7Lt3ue/