Loop through an array in vlang

Question

How can I loop over an array of strings on v programming language?
For example: langs := ['python', 'java', 'javascript']

here your answer. https://vlang.io/docs#for – IMParasharG Jul 09 '19 at 12:15 — IMParasharG, Jul 09 '19 at 12:15

navule · Accepted Answer · 2019-11-05T10:14:12.597

Method 1: For loop with index

langs := ['python', 'java', 'javascript']

for i, lang in langs {
    println('$i) $lang')
}

Method 1 Output:

0) python
1) java
2) javascript

Try method 1 on vlang's playground here

Method 2: For loop without index

langs := ['python', 'java', 'javascript']

for lang in langs {
    println(lang)
}

Method 2 Output:

python
java
javascript

Try method 2 on vlang's playground here

Method 3: While loop style iteration using for in V Lang You can do this too. Following loop is similar to while loop in other languages.

mut num := 0
langs := ['python', 'java', 'javascript']

for{
    if num < langs.len {
        println(langs[num])
    }
    else{
        break
    }
    num++
}

Method 3 Output:

python
java
javascript

Try method 3 on vlang's playground here

Method 4: Looping over elements of an array by accessing its index

langs := ['python', 'java', 'javascript']

mut i := 0
for i < langs.len {
    println(langs[i])
    i++
}

Method 4 Output:

python
java
javascript

Try method 4 on V lang's playground here

Method 5: Traditional C-Style looping

As suggested by @Astariul in the comments

langs := ['python', 'java', 'javascript']

for i := 0; i < langs.len; i++ {
    println(langs[i])
}

Method 5 Output:

python
java
javascript

Try method 5 on V lang's playground here

You can checkout this playlist for more interesting vlang tutorials

Note : you can also use a C-style loop (looping over the indexes of the array) — Astariul, Aug 20 '19 at 00:39
@Astariul, added it as method 4. Hope that is what you're suggesting for — navule, Aug 20 '19 at 03:50
I was more thinking of the loop where i is declared inside the loop (`for i := 0; i < langs.len; i++`), as described in the [documentation of V](https://vlang.io/docs#for). But this one works too ^^ Thanks for keeping the answer updated :) — Astariul, Aug 20 '19 at 04:20

MosheZada · Answer 2 · 2019-07-10T16:22:53.383

1

V has only one looping construct: for.
In order to loop over the array langs, you need to use the for loop.

langs := ['python', 'java', 'javascript']
for lang in langs {
    println(lang)
}

The for value in loop is used for going through elements of an array. If an index is required, an alternative form for index, value in can be used.

edited Jul 10 '19 at 16:22

answered Jul 09 '19 at 12:11

MosheZada

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Loop through an array in vlang

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