KOTLIN: For Loop - Revision history

Onnowpurbo at 04:09, 25 July 2022

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Onnowpurbo at 03:08, 22 July 2022

2022-07-22T03:08:09Z

Onnowpurbo: Created page with "Sumber: https://www.tutorialspoint.com/kotlin/kotlin_for_loop.htm What are loops? Imagine a situation when you need to print a sentence 20 times on your screen. You can do it..."

2022-07-18T01:13:00Z

Created page with "Sumber: https://www.tutorialspoint.com/kotlin/kotlin_for_loop.htm What are loops? Imagine a situation when you need to print a sentence 20 times on your screen. You can do it..."

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Sumber: https://www.tutorialspoint.com/kotlin/kotlin_for_loop.htm

What are loops?
Imagine a situation when you need to print a sentence 20 times on your screen. You can do it by using print statement 20 times. What about if you need to print the same sentence one thousand times? This is where we need to use loops to simplify the programming job. Actually, Loops are used in programming to repeat a specific block of code until certain condition is met.

Kotlin supports various types of loops and in this chapter we are going to learn Kotlin for loop.

Kotlin For Loop
Kotlin for loop iterates through anything that provides an iterator ie. that contains a countable number of values, for example arrays, ranges, maps or any other collection available in Kotlin. Kotlin for loop is equivalent to the foreach loop in languages like C#.

Kotlin does not provide a conventional for loop which is available in C, C++ and Java etc.
Syntax
The syntax of the Kotlin for loop is as follows:

for (item in collection) {
// body of loop
}
Iterate Through a Range
We will study Kotlin Ranges in a separate chapter, for now you should know that Kotlin Ranges provide iterator, so we can iterate through a range using for loop.

Following is an example where the loop iterates through the range and prints individual item. To iterate over a range of numbers, we will use a range expression:

fun main(args: Array<String>) {
for (item in 1..5) {
println(item)
}
}
When you run the above Kotlin program, it will generate the following output:

1
2
3
4
5
Let's see one more example where the loop will iterate through another range, but this time it will step down instead of stepping up as in the above example:

fun main(args: Array<String>) {
for (item in 5 downTo 1 step 2) {
println(item)
}
}
When you run the above Kotlin program, it will generate the following output:

5
3
1
Iterate Through a Array
Kotlin Array is another data type which provides iterator, so we can use for loop to iterate through a Kotlin array in the similar way as we did it for the ranges.

Following is an example where we used for loop to iterate through an array of strings:

fun main(args: Array<String>) {
var fruits = arrayOf("Orange", "Apple", "Mango", "Banana")

for (item in fruits) {
println(item)
}
}
When you run the above Kotlin program, it will generate the following output:

Orange
Apple
Mango
Banana
Let's see the same example once again, but this time we will iterate through the array using its index.

fun main(args: Array<String>) {
var fruits = arrayOf("Orange", "Apple", "Mango", "Banana")

for (index in fruits.indices) {
println(fruits[index])
}
}
When you run the above Kotlin program, it will generate the following output:

Orange
Apple
Mango
Banana
Quiz Time (Interview & Exams Preparation)
Q 1 - Which of the following is true about Kotlin for loop?

A - It is used to loop through an iterator.

B - Kotlin does not provide conventional for loop like C, C++ or Java.

C - Kotlin for loop is equivalent to the foreach loop in languages like C#.

D - All of the above

Q 2 - What will be the last number printed by the following for loop?

fun main(args: Array<String>) {
for (item in 6 downTo 1 step 2) {
println(item)
}
}
A - 6

B - 5

C - 3

D - 2

==Referensi==

* https://www.tutorialspoint.com/kotlin/kotlin_for_loop.htm

@@ Line 6: / Line 6: @@
 Kotlin supports various types of loops and in this chapter we are going to learn Kotlin for loop.
 ==Kotlin For Loop==
@@ Line 12: / Line 20: @@
 Kotlin does not provide a conventional for loop which is available in C, C++ and Java etc.
 ===Syntax===
 The syntax of the Kotlin for loop is as follows:
   for (item in collection) {
@@ Line 26: / Line 43: @@
 Following is an example where the loop iterates through the range and prints individual item. To iterate over a range of numbers, we will use a range expression:
   fun main(args: Array<String>) {
@@ Line 34: / Line 58: @@
 When you run the above Kotlin program, it will generate the following output:
@@ Line 42: / Line 69: @@
 Let's see one more example where the loop will iterate through another range, but this time it will step down instead of stepping up as in the above example:
   fun main(args: Array<String>) {
@@ Line 50: / Line 80: @@
 When you run the above Kotlin program, it will generate the following output:
@@ Line 60: / Line 93: @@
 Following is an example where we used for loop to iterate through an array of strings:
   fun main(args: Array<String>) {
@@ Line 70: / Line 109: @@
 When you run the above Kotlin program, it will generate the following output:
   Orange
@@ Line 77: / Line 118: @@
 Let's see the same example once again, but this time we will iterate through the array using its index.
   fun main(args: Array<String>) {
@@ Line 87: / Line 131: @@
 When you run the above Kotlin program, it will generate the following output:
   Orange

← Older revision		Revision as of 03:08, 22 July 2022
Line 1:		Line 1:
	Sumber: https://www.tutorialspoint.com/kotlin/kotlin_for_loop.htm		Sumber: https://www.tutorialspoint.com/kotlin/kotlin_for_loop.htm

−	What are loops?	+	==What are loops?==
		+
	Imagine a situation when you need to print a sentence 20 times on your screen. You can do it by using print statement 20 times. What about if you need to print the same sentence one thousand times? This is where we need to use loops to simplify the programming job. Actually, Loops are used in programming to repeat a specific block of code until certain condition is met.		Imagine a situation when you need to print a sentence 20 times on your screen. You can do it by using print statement 20 times. What about if you need to print the same sentence one thousand times? This is where we need to use loops to simplify the programming job. Actually, Loops are used in programming to repeat a specific block of code until certain condition is met.

	Kotlin supports various types of loops and in this chapter we are going to learn Kotlin for loop.		Kotlin supports various types of loops and in this chapter we are going to learn Kotlin for loop.

−	Kotlin For Loop	+	==Kotlin For Loop==
		+
	Kotlin for loop iterates through anything that provides an iterator ie. that contains a countable number of values, for example arrays, ranges, maps or any other collection available in Kotlin. Kotlin for loop is equivalent to the foreach loop in languages like C#.		Kotlin for loop iterates through anything that provides an iterator ie. that contains a countable number of values, for example arrays, ranges, maps or any other collection available in Kotlin. Kotlin for loop is equivalent to the foreach loop in languages like C#.

	Kotlin does not provide a conventional for loop which is available in C, C++ and Java etc.		Kotlin does not provide a conventional for loop which is available in C, C++ and Java etc.
−	Syntax	+
		+	===Syntax===
		+
	The syntax of the Kotlin for loop is as follows:		The syntax of the Kotlin for loop is as follows:

−	for (item in collection) {	+	for (item in collection) {
−	// body of loop	+	// body of loop
−	}	+	}
−	Iterate Through a Range	+
		+	==Iterate Through a Range==
		+
	We will study Kotlin Ranges in a separate chapter, for now you should know that Kotlin Ranges provide iterator, so we can iterate through a range using for loop.		We will study Kotlin Ranges in a separate chapter, for now you should know that Kotlin Ranges provide iterator, so we can iterate through a range using for loop.

	Following is an example where the loop iterates through the range and prints individual item. To iterate over a range of numbers, we will use a range expression:		Following is an example where the loop iterates through the range and prints individual item. To iterate over a range of numbers, we will use a range expression:

−	fun main(args: Array<String>) {	+	fun main(args: Array<String>) {
−	for (item in 1..5) {	+	for (item in 1..5) {
−	println(item)	+	println(item)
−	}	+	}
−	}	+	}
		+
	When you run the above Kotlin program, it will generate the following output:		When you run the above Kotlin program, it will generate the following output:

−	1	+	1
−	2	+	2
−	3	+	3
−	4	+	4
−	5	+	5
		+
	Let's see one more example where the loop will iterate through another range, but this time it will step down instead of stepping up as in the above example:		Let's see one more example where the loop will iterate through another range, but this time it will step down instead of stepping up as in the above example:

−	fun main(args: Array<String>) {	+	fun main(args: Array<String>) {
−	for (item in 5 downTo 1 step 2) {	+	for (item in 5 downTo 1 step 2) {
−	println(item)	+	println(item)
−	}	+	}
−	}	+	}
		+
	When you run the above Kotlin program, it will generate the following output:		When you run the above Kotlin program, it will generate the following output:

−	5	+	5
−	3	+	3
−	1	+	1
−	Iterate Through a Array	+
		+	==Iterate Through a Array==
		+
	Kotlin Array is another data type which provides iterator, so we can use for loop to iterate through a Kotlin array in the similar way as we did it for the ranges.		Kotlin Array is another data type which provides iterator, so we can use for loop to iterate through a Kotlin array in the similar way as we did it for the ranges.

	Following is an example where we used for loop to iterate through an array of strings:		Following is an example where we used for loop to iterate through an array of strings:

−	fun main(args: Array<String>) {	+	fun main(args: Array<String>) {
−	var fruits = arrayOf("Orange", "Apple", "Mango", "Banana")	+	var fruits = arrayOf("Orange", "Apple", "Mango", "Banana")
−		+
−	for (item in fruits) {	+	for (item in fruits) {
−	println(item)	+	println(item)
−	}	+	}
−	}	+	}
		+
	When you run the above Kotlin program, it will generate the following output:		When you run the above Kotlin program, it will generate the following output:

−	Orange	+	Orange
−	Apple	+	Apple
−	Mango	+	Mango
−	Banana	+	Banana
		+
	Let's see the same example once again, but this time we will iterate through the array using its index.		Let's see the same example once again, but this time we will iterate through the array using its index.

−	fun main(args: Array<String>) {	+	fun main(args: Array<String>) {
−	var fruits = arrayOf("Orange", "Apple", "Mango", "Banana")	+	var fruits = arrayOf("Orange", "Apple", "Mango", "Banana")
−		+
−	for (index in fruits.indices) {	+	for (index in fruits.indices) {
−	println(fruits[index])	+	println(fruits[index])
−	}	+	}
−	}	+	}
		+
	When you run the above Kotlin program, it will generate the following output:		When you run the above Kotlin program, it will generate the following output:

−	Orange	+	Orange
−	Apple	+	Apple
−	Mango	+	Mango
−	Banana	+	Banana
−	Quiz Time (Interview & Exams Preparation)	+
		+	==Quiz Time (Interview & Exams Preparation)==
		+
	Q 1 - Which of the following is true about Kotlin for loop?		Q 1 - Which of the following is true about Kotlin for loop?