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dddenis
Asked: 2020-06-15 16:00:29 +0800 CST 2020-06-15 16:00:29 +0800 CST

Join Arrays without using the concat method and return it in a new Array

  • 772

I'm doing a simple exercise to do iteratively or with the method concat, which consists of joining 2 arrays and returning the joined as a new array , but I can't, this is the code I have, as a premise, it must be in one line, hence it does not end up solving it.

Array.prototype.concatenar = function(vector) {
    let nuevoVector = this;
    nuevoVector.push.apply(this, vector);
    return nuevoVector;
};

I don't understand how to resolve in a new array or obtain a result of joining them and returning it in the same line, I have tried the method mapof traversing the received vector and adding it to the vector this , but nothing...

javascript

2 Answers

  1. Best Answer

    You can use the operator ...with the Arrays:

    Array.prototype.concatenarArray = function(array){
  return [...this, ...array];
}

console.log([1, 2, 3].concatenarArray([1]));

    DOCUMENTATION

    EDIT

    You can even make a function that concatenates more than one Array:

    Array.prototype.concatenarArrays = function(...arrays){
  return [...this, ...arrays.reduce((anterior, actual)=>
    anterior.push(...actual) && anterior, [])];
}

console.log([1,2,3].concatenarArrays([1], [2,3]));

    • 4

  2. I think what you want to do is this...

    • You create the new array.
    • You push both arrays into the resulting one.
    • you return the result.

    Array.prototype.concatenar = function(otro) {
    let nuevo = [];
    Array.prototype.push.apply(nuevo, this);
    Array.prototype.push.apply(nuevo, otro);
    return nuevo;
};

console.log([1,2,3].concatenar([4,5,6]));

    • 2