In this example, we’re appending the List of elements of type Integer returned by the filterIsInstanceTo() function to the mutableList. The predicates are simple lambda expressions.

We use predicates to define the filtering conditions. These functions return a new List and are usable for both read-only and mutable Lists. Subsequently, we can use the filterIsInstanceTo() function to append a List of elements of a specified type to the destination List: val countr圜ode = listOf('Germany', 49, null, 'India', 91, 'Japan', 81, 'Brazil', null, 'Australia', 61)ĪssertTrue(ntainsAll(listOf(1,24,49,91,81,61))) The standard Kotlin library provides many beneficial functions to filter a List. In this case, we’re using the filterIsInstance() function to return a List of elements of type Integer. Val filterList = countr圜ode.filterIsInstance()ĪssertTrue(ntainsAll(listOf(49,91,81,61))) The filterIsInstance() function can be used to return a List of elements of a specified type: val countr圜ode = listOf('Germany', 49, null, 'India', 91, 'Japan', 81, 'Brazil', null, 'Australia', 61) In this example, the filterIndexedTo() function appends the resulting two elements matching the predicate to the mutableList. It then returns a List of elements matching the given predicate: val filterList = countries.filterIndexed )ĪssertTrue(ntainsAll(listOf('United States','Canada','Germany','Australia')))

The predicate of this function uses both the index and the element as arguments. We can use the filterIndexed() function to utilize the element position in the filter.

Kotlin list to string