Gradle Single vs Double Quotes

Question

I'm new to gradle and am currently just trying to follow the tutorials and quite a few times I've seen single and double quotes intermixed. I just wanted to know if there was a difference of when one set should be used over the other. One example of this is section 6.12 of the tutorial - Default tasks:

defaultTasks 'clean', 'run'

task clean << {
    println 'Default Cleaning!'
}

task run << {
    println 'Default Running!'
}

task other << {
    println "I'm not a default task!"
}

So, I would just like to know if I should be paying attention to these differences or if they are inter-changable and I can use either single or double quotes when printing strings in gradle.

https://stackoverflow.com/questions/6761498/whats-the-difference-of-strings-within-single-or-double-quotes-in-groovy — NoDataDumpNoContribution, May 24 '18 at 11:08

score 86 · Accepted Answer · answered Mar 02 '13 at 07:53

86

Gradle build scripts are written in Groovy. Groovy has both double-quoted and single-quoted String literals. The main difference is that double-quoted String literals support String interpolation:

def x = 10
println "result is $x" // prints: result is 10

You can learn more about Groovy String interpolation in this or other Groovy articles on the web.

answered Mar 02 '13 at 07:53

Peter Niederwieser

121,412
21
324
259

3

Thanks for the clear explanation. But now I have a follow up question, is there any reason to not always use double quotes then? – Dan W Mar 02 '13 at 15:31
7

Mostly subjective/situational ones like "looks better", "used to this style from another language", "want to use literal `$` or `"` without having to escape them", "easier to type". Many Groovy users seem to prefer single quotes by default. I prefer double quotes because they allow me to add/remove String interpolation without changing the quotes. Also I'm used to double quotes from languages like Java. – Peter Niederwieser Mar 03 '13 at 09:52

JB Nizet · Answer 2 · 2013-03-02T11:50:13.033

14

Yes, you can use one or the other. The only difference is that double-quoted strings can be GStrings, which can contain evaluated expressions like in the following example taken from the Groovy documentation:

foxtype = 'quick'
foxcolor = ['b', 'r', 'o', 'w', 'n']
println "The $foxtype ${foxcolor.join()} fox"
// => The quick brown fox

edited Mar 02 '13 at 11:50

answered Mar 02 '13 at 07:52

JB Nizet

678,734
91
1,224
1,255

3

Double-quoted string literals are `GString`s iff they contain a `$`. Otherwise, they are plain `String`s. – Peter Niederwieser Mar 02 '13 at 11:32

score 7 · Answer 3 · edited Jun 20 '20 at 09:12

7

According to the gradle docs:

Favor single quotes for plain strings in build script listings

This is mostly to ensure consistency across guides, but single quotes are also a little less noisy than double quotes. Only use double quotes if you want to include an embedded expression in the string.

edited Jun 20 '20 at 09:12

Community

1
1

answered Feb 01 '19 at 02:06

Julian A.

10,928
16
67
107

2

Looks like that guide and guidance has disappeared. – Dave L. May 18 '20 at 00:18
@DaveL. Yeah, and I can't find it anywhere else. – Julian A. May 18 '20 at 19:00
1

Found some similar guidance here - https://groovy-lang.org/style-guide.html "Last but not least, prefer using single quoted strings when you need string constants, and use double quoted strings when you are explicitly relying on string interpolation." – AlgoRyan Jul 06 '20 at 02:35
imo, mixing is much more noisy than only using double quotes. – Android Feb 15 '21 at 07:40

score 2 · Answer 4 · answered Jan 10 '19 at 06:20

Single-quoted strings are a series of characters surrounded by single quotes. like :

def str='a single quoted string'
println str

Ouput :

a single quoted string

Whereas Double-quoted strings allow us the String interpolation Here, we have a string with a placeholder referencing a local variable:

def name = 'Guillaume' // a plain string
def greeting = "Hello ${name}"

Output : Hello Guillaume

In your code,If you want to print the task name. So in that case, you need to use Double-quotes:

defaultTasks 'clean', 'run'

task clean << {
    println 'Default Cleaning!'
}

task run << {
    println "Default Running $run.name!"
    // here Double Quotes are required to interpolate task-name
}

task other << {
    println "I'm not a default task!"
}

Mahozad · Answer 5 · 2022-05-04T07:59:00.467

0

Kotlin DSL files (like build.gradle.kts or settings.gradle.kts) are regular Kotlin code.
So, string literals are always wrapped in double quotes:

val myFirstString = "4 / 2 equals ${4 / 2}"
val mySecondString = """The property "hide" was not found"""

edited May 04 '22 at 07:59

answered Feb 18 '22 at 14:27

Mahozad

18,032
13
118
133

Gradle Single vs Double Quotes

5 Answers5

Linked