When to use Float32Array instead of Array in JavaScript

pancake提出了一个问题:When to use Float32Array instead of Array in JavaScript,或许与您遇到的问题类似。


I emailed the developer of glMatrix and my answer below includes his comments (points 2 & 3):

  1. Creating a new object is generally quicker with Array than Float32Array. The gain is significant for small arrays, but is less (environment dependent) with larger arrays.

  2. Accessing data from a TypedArray (eg. Float32Array) is often faster than from a normal array, which means that most array operations (aside from creating a new object) are faster with TypedArrays.

  3. As also stated by @emidander, glMatrix was developed primarily for WebGL, which requires that vectors and matrices be passed as Float32Array. So, for a WebGL application, the potentially costly conversion from Array to Float32Array would need to be included in any performance measurement.

So, not surprisingly, the best choice is application dependent:

  • If arrays are generally small, and/or number of operations on them is low so that the constructor time is a significant proportion of the array's lifespan, use Array.

  • If code readability is as important as performance, then use Array (i.e. use [], instead of a constructor).

  • If arrays are very large and/or are used for many operations, then use a TypedArray.

  • For WebGL applications (or other applications that would otherwise require a type conversion), use Float32Array (or other TypedArray).