74,494 questions
1438
votes
12
answers
1.6m
views
How to check if a map contains a key in Go?
I know I can iterate over a map m with
for k, v := range m { ... }
and look for a key, but is there a more efficient way of testing for a key's existence in a map?
- 19.4k
1020
votes
20
answers
801k
views
How to efficiently concatenate strings in go
In Go, a string is a primitive type, which means it is read-only, and every manipulation of it will create a new string.
So if I want to concatenate strings many times without knowing the length of ...
- 73.8k
959
votes
13
answers
579k
views
How do you write multiline strings in Go?
Does Go have anything similar to Python's multiline strings:
"""line 1
line 2
line 3"""
If not, what is the preferred way of writing strings spanning multiple lines?
- 12.9k
861
votes
11
answers
714k
views
Concatenate two slices in Go
I'm trying to combine the slice [1, 2] and the slice [3, 4]. How can I do this in Go?
I tried:
append([]int{1,2}, []int{3,4})
but got:
cannot use []int literal (type []int) as type int in append
...
- 65.8k
844
votes
11
answers
883k
views
How to convert an int value to string in Go?
i := 123
s := string(i)
s is 'E', but what I want is "123"
Please tell me how can I get "123".
- 21.2k
825
votes
15
answers
702k
views
What is an idiomatic way of representing enums in Go?
I'm trying to represent a simplified chromosome, which consists of N bases, each of which can only be one of {A, C, T, G}.
I'd like to formalize the constraints with an enum, but I'm wondering what ...
- 9,668
817
votes
15
answers
608k
views
Optional Parameters in Go?
Can Go have optional parameters? Or can I just define two different functions with the same name and a different number of arguments?
- 17.6k
810
votes
9
answers
693k
views
Is there a foreach loop in Go?
Is there a foreach construct in the Go language?
Can I iterate over a slice or array using a for?
- 25.9k
759
votes
19
answers
833k
views
How to print struct variables in console?
How can I print (to the console) the Id, Title, Name, etc. of this struct in Golang?
type Project struct {
Id int64 `json:"project_id"`
Title string `json:"title"`...
- 9,807
727
votes
15
answers
570k
views
How to check if a file exists in Go?
Does the Go standard library have a function which checks if a file exists (like Python's os.path.exists).
Is there an idiomatic way to check file existence / non-existence?
- 86.5k
624
votes
14
answers
576k
views
What is the idiomatic Go equivalent of C's ternary operator?
In C/C++ (and many languages of that family), a common idiom to declare and initialize a variable depending on a condition uses the ternary conditional operator :
int index = val > 0 ? val : -val
...
- 13.6k
619
votes
4
answers
194k
views
What are the use(s) for struct tags in Go?
In the Go Language Specification, it mentions a brief overview of tags:
A field declaration may be followed by an optional string literal tag,
which becomes an attribute for all the fields in the ...
- 14.6k
600
votes
16
answers
707k
views
How to find the type of an object in Go?
How do I find the type of an object in Go? In Python, I just use typeof to fetch the type of object. Similarly in Go, is there a way to implement the same ?
Here is the container from which I am ...
- 11.8k
590
votes
13
answers
665k
views
Reading a file line by line in Go
I'm unable to find file.ReadLine function in Go.
How does one read a file line by line?
- 6,225
587
votes
8
answers
461k
views
Format a Go string without printing?
Is there a simple way to format a string in Go without printing the string?
I can do:
bar := "bar"
fmt.Printf("foo: %s", bar)
But I want the formatted string returned rather than printed so I can ...
- 6,005