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Check if an array of arrays contains a value in javascript

I know that if there is an array of values it must be used this approach:
console.log(['joe', 'jane', 'mary'].includes('jane')); // true
But in case of an array of arrays, is there a short way to do it? Without other computations between.
For this input:
[['jane'],['joe'],['mary']]

You can use flat method to flatten the array. For more neted array, you can also mention depth like flat(depth)
let arr = [["jane"],["joe"],["mary"]];
arr.flat().includes('jane'); //true

You can easily achieve this result using some
arr.some((a) => a.includes("jane"))
const arr = [
["jane"],
["joe"],
["mary"]
];
const arr2 = [
["joe"],
["mary"]
];
console.log(arr.some((a) => a.includes("jane")));
console.log(arr2.some((a) => a.includes("jane")));

it can also be done by first flattening the 2d arrays in 1 d aaray and then using includes to find whether the array contains the element or not
var arr = [['jane'],['joe'],['marry']]
var newarr=[].concat(...arr)
var v=newarr.includes('jane')
console.log(v)

How to destructure an array of objects? [duplicate]

In its most basic form, having an array of objects:
let arr = [
{val:"a"},
{val:"b"}
];
How can destructuring be used, to obtain only the values ['a', 'b'].
getting the first value is easy:
let [{val:res}] = arr; //res contains 'a'
Obtaining all values inside the array can be done with the rest operator:
let [...res] = arr; //res contains all objects
Combining those, I expected to be able to use:
let [...{val:res}] = arr; //undefined, expected all 'val's (['a', 'b'])
The above returns undefined (Tested in FF). Some further testing seems to indicate that adding the rest operator when using an object destructuring as well doesn't use the iteration, but gets back the original object, e.g. let [...{length:res}] = arr; //res= 2. Some other trials, such as let [{val:...res}] = arr; or let [{val}:...res] = arr; produce syntax errors.
It's easy enough to do with other methods, such as using map on the array, but mostly I stumble upon this problem while destructuring multiple levels (an array with objects which have their own property containing an array). Therefore I'm really trying to get around how to do it solely with destructuring.
For convenience: a test fiddle
edit
My apologies if I failed to explain the goal of the question. I'm not looking for a solution to a specific problem, only to find the correct syntax to use when destructuring.
Otherwise formulated, a first question would be: in the example above, why doesn't let [...{val:res}] = arr; return all values (['a', 'b']). The second question would be: what is the proper syntax to use a rest operator with a nested object destructuring? (pretty sure I've gotten some definitions mixed up here). It seems that the latter is not supported, but I haven't come across any documentation that (and why) it wouldn't be.

Why doesn't let [...{val:res}] = arr; return all values (['a', 'b'])?
You seem to confuse the rest syntax with array comprehensions.
If you assign a value to [someElements, ...someExpression], the value is tested to be iterable and then each element generated by the iterator is assigned to the respective someElements variable. If you use the rest syntax in the destructuring expression, an array is created and the iterator is ran till its end while filling the array with the generated values. Then that array is assigned to the someExpression.
All of these assignment targets can be other destructuring expressions (arbitrarily nested and recursively evaluated), or references to variable or properties.
So if you do let [...{val:res}] = arr, it will create an array and fill that with all the values from the iterator of arr:
let {val:res} = Array.from(arr[Symbol.iterator]())
You can see now why that ends up with undefined, and why using something like [...{length:res}] does yield a result. Another example:
let [{val:res1}, ...{length: res2}] = arr;
console.log(res1) // 'a'
console.log(res2) // 1 (length of `[{val: 'b'}]`)
How can destructuring be used to obtain only the values ['a', 'b']?
Not at all. Use the map method.

You can destructure nested objects like this
https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment#Nested_object_and_array_destructuring
let arr = [
{val:"a"},
{val:"b"}
];
const [{val: valueOfA}, {val: valueOfB}] = arr
console.log(
valueOfA, valueOfB
)

Beside mapping with a callback for the value
let arr = [{ val: "a" }, { val: "b" }];
console.log(arr.map(o => o.val));
you could use deconstructiong inside of the paramter list and use only the value to return.
let arr = [{ val: "a" }, { val: "b" }];
console.log(arr.map(({val}) => val));

At this point of time you can use both For of loop with ES6 Object destructuring.
let arr = [{val:"a"},{val:"b"}];
for (const item in arr){
const {val} = arr[item];
console.log(val);
}

You can declare assignment target before destructuring assignment; at destructuring target, set values of assignments target indexes by from destructuring source
let arr1 = [{val: "a"}, {val: "b"}];
let arr2 = [{"foo":1,"arr":[{"val":"a"},{"val":"b"}]}
, {"foo":2,"arr":[{"val":"c"},{"val":"d"}]}];
let [res1, res2] = [[], []];
[{val: res1[0]}, {val: res1[1]}] = arr1;
[{arr: [{val:res2[0]}, {val:res2[1]}]}
, {arr: [{val:res2[2]}, {val:res2[3]}]}] = arr2;
console.log(res1, res2);
You can alternatively use rest element at target to collect values at source by including comma operator following object pattern to return value pulled from object
let arr = [{val: "a"}, {val: "b"}];
let [...res] = [({val} = arr[0], val), ({val} = arr[1], val)];
console.log(res)

Push unique objects into array in JAVASCRIPT

I want to push object that only have unique id1 into array.
Example:
let array = [],
obj = {},
access = true
if(access){
obj['id1'] = 1
obj['id2'] = 2
if(array.indexOf(obj.id1) == -1){
array.push(obj)
}
}
console.log(array);
In the above example I am trying to add value to obj then push the obj into array. But obj.id1 need to be unique. The method I am using above doesn't work in my case.
Thank you

As Taplar says, indexOf will look for the first instance of the thing you pass in in the other array. This won't work because there are no instances of the ids in the array, directly anyway.
Use the find function, which allow you pass in a comparison function, so you can define what a match is.
let initial = [{id:1}, {id:2}, {id:1}];
let result = initial.reduce((acc, item) =>
{
if(!acc.find(other => item.id == other.id))
{
acc.push(item);
}
return acc;
}, []);
console.log(result);

Simplest solution . Lets say myObjArray have duplicate object use below es6 code to get unique array from that
// Creates an array of objects with unique "name" property values.
let uniqueObjArray = [
...new Map(myObjArray.map((item) => [item["name"], item])).values(), ]; console.log("uniqueObjArray", uniqueObjArray);
Refer here for more detail https://yagisanatode.com/2021/07/03/get-a-unique-list-of-objects-in-an-array-of-object-in-javascript/

I think you need to use findIndex and not indexOf.
Try replacing your if condition with the following:
array.findIndex((o)=>{ return o.id1 === obj.id1 }) === -1

How to get the name from the array in javascript?

I am fairly new to JavaScript and I am trying to extract the name Sam from the array. The output that I'm getting is name. How do I get Sam? Thank you in advance. I apologize but I know this is a fairly novice question.
I am trying to loop by using forEach.
let Person = {
name: ['Sam']
}
let handler = Object.keys(Person)
handler.forEach(function(element){
console.log(element)
})

Object.keys() only gives you keys
Use Object.entries() if you want key and value
Use Object.values() if you only want values
let Person = {
name: ['Sam']
}
for (const fn of ["values", "keys", "entries"]) {
console.log(`Using: Object.${fn}()`);
for (const v of Object[fn](Person)) {
console.log(v);
}
}

Instead of Object.keys use Object.values

If you know in advance that your name array is located under the key name, then access it directly
const person = { name: ['Sam'] };
console.log(person.name);
console.log(person.name[0]);
Otherwise, use Object.values() to enumerate the values in the object, but you might get more values than simply the names array and you will have to find out which value contains the names you are looking for:
const person = { name: ['Sam'], anotherProp: 'hello' };
console.log(Object.values(person));
Using Object.entries() is not helpful in this situation as if you use it, it means that you know under which property is located your name array, and if this is the case, simply access the array directly.

let Person = {
name: ['Sam',"Bob","Alice"]
}
let count = Person.name.length;
for(let i = 0; i<count; i++){
console.log( Person.name[i])
}

If you use Object.keys() you can get the value by using object[key] bracket notation or object.key dot notation.
Object.keys(obj).forEach(key => obj[key]);
let Person = {
name: ['Sam']
}
Object.keys(Person).forEach(name => console.log(`${name} = ${Person[name]}`));

Destructure object properties inside array for all elements

In its most basic form, having an array of objects:
let arr = [
{val:"a"},
{val:"b"}
];
How can destructuring be used, to obtain only the values ['a', 'b'].
getting the first value is easy:
let [{val:res}] = arr; //res contains 'a'
Obtaining all values inside the array can be done with the rest operator:
let [...res] = arr; //res contains all objects
Combining those, I expected to be able to use:
let [...{val:res}] = arr; //undefined, expected all 'val's (['a', 'b'])
The above returns undefined (Tested in FF). Some further testing seems to indicate that adding the rest operator when using an object destructuring as well doesn't use the iteration, but gets back the original object, e.g. let [...{length:res}] = arr; //res= 2. Some other trials, such as let [{val:...res}] = arr; or let [{val}:...res] = arr; produce syntax errors.
It's easy enough to do with other methods, such as using map on the array, but mostly I stumble upon this problem while destructuring multiple levels (an array with objects which have their own property containing an array). Therefore I'm really trying to get around how to do it solely with destructuring.
For convenience: a test fiddle
edit
My apologies if I failed to explain the goal of the question. I'm not looking for a solution to a specific problem, only to find the correct syntax to use when destructuring.
Otherwise formulated, a first question would be: in the example above, why doesn't let [...{val:res}] = arr; return all values (['a', 'b']). The second question would be: what is the proper syntax to use a rest operator with a nested object destructuring? (pretty sure I've gotten some definitions mixed up here). It seems that the latter is not supported, but I haven't come across any documentation that (and why) it wouldn't be.

Why doesn't let [...{val:res}] = arr; return all values (['a', 'b'])?
You seem to confuse the rest syntax with array comprehensions.
If you assign a value to [someElements, ...someExpression], the value is tested to be iterable and then each element generated by the iterator is assigned to the respective someElements variable. If you use the rest syntax in the destructuring expression, an array is created and the iterator is ran till its end while filling the array with the generated values. Then that array is assigned to the someExpression.
All of these assignment targets can be other destructuring expressions (arbitrarily nested and recursively evaluated), or references to variable or properties.
So if you do let [...{val:res}] = arr, it will create an array and fill that with all the values from the iterator of arr:
let {val:res} = Array.from(arr[Symbol.iterator]())
You can see now why that ends up with undefined, and why using something like [...{length:res}] does yield a result. Another example:
let [{val:res1}, ...{length: res2}] = arr;
console.log(res1) // 'a'
console.log(res2) // 1 (length of `[{val: 'b'}]`)
How can destructuring be used to obtain only the values ['a', 'b']?
Not at all. Use the map method.

You can destructure nested objects like this
https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Operators/Destructuring_assignment#Nested_object_and_array_destructuring
let arr = [
{val:"a"},
{val:"b"}
];
const [{val: valueOfA}, {val: valueOfB}] = arr
console.log(
valueOfA, valueOfB
)

Beside mapping with a callback for the value
let arr = [{ val: "a" }, { val: "b" }];
console.log(arr.map(o => o.val));
you could use deconstructiong inside of the paramter list and use only the value to return.
let arr = [{ val: "a" }, { val: "b" }];
console.log(arr.map(({val}) => val));

At this point of time you can use both For of loop with ES6 Object destructuring.
let arr = [{val:"a"},{val:"b"}];
for (const item in arr){
const {val} = arr[item];
console.log(val);
}

You can declare assignment target before destructuring assignment; at destructuring target, set values of assignments target indexes by from destructuring source
let arr1 = [{val: "a"}, {val: "b"}];
let arr2 = [{"foo":1,"arr":[{"val":"a"},{"val":"b"}]}
, {"foo":2,"arr":[{"val":"c"},{"val":"d"}]}];
let [res1, res2] = [[], []];
[{val: res1[0]}, {val: res1[1]}] = arr1;
[{arr: [{val:res2[0]}, {val:res2[1]}]}
, {arr: [{val:res2[2]}, {val:res2[3]}]}] = arr2;
console.log(res1, res2);
You can alternatively use rest element at target to collect values at source by including comma operator following object pattern to return value pulled from object
let arr = [{val: "a"}, {val: "b"}];
let [...res] = [({val} = arr[0], val), ({val} = arr[1], val)];
console.log(res)