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Aug 13, 2023CAS
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Untitled

Apr 26, 2025hasnaoui1

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console.log("xa")

tree traversal

Nov 19, 2022CodeCatch

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class TreeNode {
constructor(key, value = key, parent = null) {
this.key = key;
this.value = value;
this.parent = parent;
this.children = [];
}
get isLeaf() {
return this.children.length === 0;
}
get hasChildren() {
return !this.isLeaf;
}
}
class Tree {
constructor(key, value = key) {
this.root = new TreeNode(key, value);
}
*preOrderTraversal(node = this.root) {
yield node;
if (node.children.length) {
for (let child of node.children) {
yield* this.preOrderTraversal(child);
}
}
}
*postOrderTraversal(node = this.root) {
if (node.children.length) {
for (let child of node.children) {
yield* this.postOrderTraversal(child);
}
}
yield node;
}
insert(parentNodeKey, key, value = key) {
for (let node of this.preOrderTraversal()) {
if (node.key === parentNodeKey) {
node.children.push(new TreeNode(key, value, node));
return true;
}
}
return false;
}
remove(key) {
for (let node of this.preOrderTraversal()) {
const filtered = node.children.filter(c => c.key !== key);
if (filtered.length !== node.children.length) {
node.children = filtered;
return true;
}
}
return false;
}
find(key) {
for (let node of this.preOrderTraversal()) {
if (node.key === key) return node;
}
return undefined;
}
}
const tree = new Tree(1, 'AB');
tree.insert(1, 11, 'AC');
tree.insert(1, 12, 'BC');
tree.insert(12, 121, 'BG');
[...tree.preOrderTraversal()].map(x => x.value);
// ['AB', 'AC', 'BC', 'BCG']
tree.root.value; // 'AB'
tree.root.hasChildren; // true
tree.find(12).isLeaf; // false
tree.find(121).isLeaf; // true
tree.find(121).parent.value; // 'BC'
tree.remove(12);
[...tree.postOrderTraversal()].map(x => x.value);
// ['AC', 'AB']

native data structures

Nov 19, 2022CodeCatch

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const nums = [1, 2, 3];
const strs = Array.from('est');
nums.push(6);
nums.push(4, 9);
strs.unshift('t');
nums.length; // 6
nums[nums.length - 1]; // 9
strs[0]; // 't'
strs[2]; // 's'
nums.slice(1, 3); // [2, 3]
nums.map(n => n * 2); // [2, 4, 6, 12, 8, 18]
nums.filter(n => n % 2 === 0); // [2, 6, 4]
nums.reduce((a, n) => a + n, 0); // 25
strs.reverse(); // ['t', 's', 'e', 't']
strs.join(''); // 'test'
const nums = new Set([1, 2, 3]);
nums.add(4);
nums.add(1);
nums.add(5);
nums.add(4);
nums.size; // 5
nums.has(4); // true
nums.delete(4);
nums.has(4); // false
[...nums]; // [1, 2, 3, 5]
nums.clear();
nums.size; // 0
const items = new Map([
[1, { name: 'John' }],
[2, { name: 'Mary' }]
]);
items.set(4, { name: 'Alan' });
items.set(2, { name: 'Jeff' });
items.size; // 3
items.has(4); // true
items.get(2); // { name: 'Jeff' }
items.delete(2);
items.size; // 2
[...items.keys()]; // [1, 4]
[...items.values()]; // [{ name: 'John' }, { name: 'Alan' }]
items.clear();
items.size; // 0

Extracting components

Nov 19, 2022CodeCatch

0 likes • 2 views

function formatDate(date) {
return date.toLocaleDateString();
}
function Comment(props) {
return (
<div className="Comment">
<div className="UserInfo">
<img
className="Avatar"
src={props.author.avatarUrl}
alt={props.author.name}
/>
<div className="UserInfo-name">
{props.author.name}
</div>
</div>
<div className="Comment-text">{props.text}</div>
<div className="Comment-date">
{formatDate(props.date)}
</div>
</div>
);
}
const comment = {
date: new Date(),
text: 'I hope you enjoy learning React!',
author: {
name: 'Hello Kitty',
avatarUrl: 'https://placekitten.com/g/64/64',
},
};
ReactDOM.render(
<Comment
date={comment.date}
text={comment.text}
author={comment.author}
/>,
document.getElementById('root')
);

UNT canvas file finder utility

Nov 18, 2022AustinLeath

0 likes • 2 views

//use this with canvas file finder
function NewTab(testing) {
window.open(testing, "_blank");
}
for(test in results) {
var testing = 'https://unt.instructure.com/files/' + test + '/download';
NewTab(testing);
}

Check if array is empty

Nov 19, 2022CodeCatch

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arr = [] // empty array
const isEmpty = arr => !Array.isArray(arr) || arr.length === 0;
// Examples
isEmpty([]); // true
isEmpty([1, 2, 3]); // false