How Can You Use Switch Statements for Greater-than/Less-than Comparisons in JavaScript?

Switch Statements for Greater-than/Less-than Comparisons

Problem:

Using switch statements with greater-than and less-than operators is not possible in JavaScript syntax. This poses a challenge when needing to perform range comparisons efficiently.

Solution:

While there are various approaches to addressing this issue, the most efficient solution varies depending on the specific use case and browser environment. Here are several tested options:

if-immediate (Immediate Conditional Statements):

<code class="javascript">if (scrollLeft < 1000) {
  // do stuff
} else if (scrollLeft > 1000 && scrollLeft < 2000) {
  // do other stuff
}

This method uses nested if statements for direct comparisons, resulting in excellent performance.

switch-immediate (Immediate Switch-Case Statements):

<code class="javascript">switch (true) {
  case scrollLeft < 1000:
    // do stuff
    break;
  case scrollLeft > 1000 && scrollLeft < 2000:
    // do other stuff
    break;
}

While it resembles a switch statement, it internally uses if statements, making it comparable to the if-immediate approach.

switch-range (Range Matching in Switch-Case Statements):

<code class="javascript">switch (true) {
  case scrollLeft >= 0 && scrollLeft < 1000: // not recommended
  case scrollLeft >= 1000 && scrollLeft < 2000:
    // do stuff
    break;
}

This approach extends the switch-immediate method to handle range comparisons. However, it may have performance implications due to potential overflow and performance penalties.

switch-range2 (Range Matching Using Variables):

<code class="javascript">const range1 = [0, 1000];
const range2 = [1000, 2000];
switch (true) {
  case scrollLeft >= range1[0] && scrollLeft < range1[1]:
  case scrollLeft >= range2[0] && scrollLeft < range2[1]:
    // do stuff
    break;
}</code>

This method uses an array of ranges to perform the comparisons. It offers a balance between performance and flexibility.

Benchmarking Results:

Browser Performance Comparison:

• if-immediate: Best performance across browsers
• switch-immediate: Comparable to if-immediate
• switch-range: Slower than if-immediate and switch-immediate
• switch-range2: Slightly faster than switch-range
• switch-indirect-array: Slowest performance involving arrays

Recommendations:

For maximum performance, use if-immediate. If performance is not a critical concern, switch-immediate or switch-range2 can be alternative options that provide the convenience of switch statements. Avoid using switch-indirect-array or array-binary-switch due to their performance penalties.

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