Add a variable to a class instance at runtime: Difference between revisions
Add a variable to a class instance at runtime (view source)
Revision as of 14:37, 9 April 2017
, 7 years agoAdded Kotlin
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e.foo = 1
e["bar"] = 2 // name specified at runtime</lang>
=={{header|Kotlin}}==
Adding variables to an object at runtime is not possible in Kotlin (at least in the version targeting the JVM) which is a statically typed language and therefore the names of all class variables need to be known at compile time.
However, as in the case of Groovy, we can ''make it appear'' as though variables are being added at runtime by using a Map or similar structure. For example:
<lang scala>// version 1.1.1
class SomeClass {
val runtimeVariables = mutableMapOf<String, Any>()
}
fun main(args: Array<String>) {
val sc = SomeClass()
println("Create two variables at runtime: ")
for (i in 1..2) {
println(" Variable #$i:")
print(" Enter name : ")
val name = readLine()!!
print(" Enter value : ")
val value = readLine()!!
sc.runtimeVariables.put(name, value)
println()
}
while (true) {
print("Which variable do you want to inspect ? ")
val name = readLine()!!
val value = sc.runtimeVariables[name]
if (value == null)
println("There is no variable of that name, try again")
else {
println("Its value is '${sc.runtimeVariables[name]}'")
return
}
}
}</lang>
{{out}}
Sample input/output:
<pre>
Create two variables at runtime:
Variable #1:
Enter name : a
Enter value : rosetta
Variable #2:
Enter name : b
Enter value : 64
Which variable do you want to inspect ? a
Its value is 'rosetta'
</pre>
=={{header|jq}}==
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