如何在Kotlin中编写for循环？Java计数式for循环的Kotlin等效代码是什么？

Hey there! Let's break down how to work with for loops in Kotlin, including the direct equivalent of the Java loop you mentioned.

1. Common For Loop Patterns in Kotlin #

Kotlin simplifies loop syntax compared to Java, with several flexible options:

• Range-based loops (most common for sequential counts)
  Use until for an exclusive upper bound (matches i < X logic) or .. for an inclusive range:

  // Exclusive range: runs i from 0 to 4 (stops before 5)
  for (i in 0 until 5) {
      // Your loop body here
  }
  
  // Inclusive range: runs i from 0 to 5 (includes 5)
  for (i in 0..5) {
      // Your loop body here
  }
  

• Loops with step increments
  If you need to skip values, add step to your range:

  // Runs i = 0, 2, 4
  for (i in 0 until 5 step 2) {
      // Your loop body here
  }
  

• Iterating over collections
  For lists, arrays, or other iterables, you can loop directly over elements without an index:

  val veggies = listOf("Carrot", "Spinach", "Broccoli")
  for (veggie in veggies) {
      println(veggie)
  }
  

2. Exact Equivalent of Your Java Loop #

Your original Java code:

for(int i = 0; i < 5 ; i++) { 
    // Loop body 
}

The Kotlin code that behaves exactly the same uses the until keyword, since it replicates the i < 5 condition perfectly:

for (i in 0 until 5) {
    // Your loop body goes here
}

If you prefer to use an inclusive range instead, you could write 0..4 (since that's 5 iterations total), but 0 until 5 is more readable here because it directly mirrors the logic from your Java code.

内容的提问来源于stack exchange，提问作者Devrath