How to create an array containing 1...N

Initialization Techniques

JavaScript arrays initialization can be accomplished in several ways. Here are a few:

• From 0 to N-1: Handy for situations where zero-based indexing is a must:

  // Because who doesn't love a good old zero-based index?
  const array0ToNMinus1 = Array.from(Array(N).keys());
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• 1 to N sequence in a previously empty array:

  // Filling up the void... with numbers!
  const sequenceArray = Array(N).fill().map((_, i) => i + 1);
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• Pre-defined sized arrays with custom or random values:

  // Let's make things interesting with some randomness.
  let filledArray = new Array(N).fill(Math.random());
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Modern JavaScript gives us the power of expressiveness and conciseness in array creation.

Making Custom Arrays

We can tailor custom arrays using the mapping function in Array.from():

• Custom values in an array:

  // Who said arrays have to be boring?
  const customValues = Array.from({ length: N }, (_, i) => `Item ${i + 1}`);
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• Random values array:

  // Because who doesn't like surprises? 
  const randomValues = Array(N).fill().map(() => Math.random());
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Practical Scenarios

Let's fetch some practical array-related tasks you'll probably stumble upon:

• Finding a value's position:

  // FBI ain't got nothing on us.
  const index = array1ToN.indexOf(someValue);
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• Creating a mid-value set:

  // Because everything is cooler in the middle.
  const middleIndexArray = [...array1ToN];
  middleIndexArray[Math.floor(N / 2)] = 'Middle Value';
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These are examples of how we use arrays in handling everyday JavaScript duties.

Compatibility Techniques

ES6 features are great, but sometimes you need to play well with older environments:

• For pre-ES5 environments, employ this method:

  // A little old school never hurt anyone.
  var arrayZeroFilled = Array.apply(null, Array(N)).map(Number.call, Number);
  

• Recursion with ES6 spread and rest:

  // Never-ending fun with recursion!
  const recursive = (n) => n ? [n, ...recursive(n - 1)] : [];
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Choose the right method for array creation by understanding your runtime environment.

Performance Optimization and Readability

Make sure your code is at its best:

• Code for performance:

  // Speed, because who doesn't like to go fast?
  const perfArray = new Array(N).fill(0);
  // Carry out your performant operations.
  

• Code for readability:

  // Because sometimes it's about the journey, not the destination.
  const readableArray = Array.from({ length: N }, (_, i) => i + 1);
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Keeping your code efficient and clear makes it both maintainable and optimized.