Merge objects into array

Just use the native method map (read more here or here) like this:

const array= [
  { "test": 1},
  { "test": 2},
  { "test": 3},
  { "test": 4},
];
const newArray = array.map(p => p.test);
console.log(JSON.stringify(newArray)); //[1,2,3,4]

Hope this helps.. ;D

You can use the map function for this https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Map :

const newarray = array.map(x => x.test);
console.log(newarray);

const result = {};

yourArray.forEach( ( object ) => {
  const keys = Object.keys( object );
  for ( let i = 0; i < keys.length; i++ ) {
     const key = keys[ i ];
     if ( ! key in result ) { 
        result[ key ] = [];
     }
     result[key] = [...result[key], ...object[key] ];
  }
});

console.log( result );

In this case:

1. You need to iterate in your array
2. On each iteration you have a new object
3. From there you iterate in all the keys of that current object
4. If the key does not exists in your result create a new empty array
5. Merge the value from the result with the current value of the object.
6. Values are stored in result.

You could map the values from the object.

const
    array = [{ test: 1 }, { test: 2 }, { test: 3 }, { test: 4 }],
    values = array.flatMap(Object.values);

console.log(values);