Groovy - Map asBoolean() method

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Description

Groovy Map asBoolean() method coerces the map to boolean value. For empty map, it returns false and for non-empty map, it returns true.

Syntax

public boolean asBoolean()

Parameters

NA

Return Value

false if map is empty else true.

Example - Coercing Map of String and String

Following is an example of the usage of this method −

main.groovy

// define a map
def map = ["A" : "Apple", "B" : "Banana", "C": "Carrot"] 

// coerce map
println(map.asBoolean())

// set map as empty
map = [:]

// coerce map
println(map.asBoolean())

Output

When we run the above program, we will get the following result −

true
false

Example - Coercing Map of Integer and Integer

Following is an example of the usage of this method −

main.groovy

// define a map
def map = [1 : 11, 2 : 12, 3: 6] 

// coerce map
println(map.asBoolean())

// set map as empty
map = [:]

// coerce map
println(map.asBoolean())

Output

When we run the above program, we will get the following result −

true
false

Example - Checking entries of a Map of Integer and Object

Following is an example of the usage of this method −

main.groovy

// define a map
def map = [1 : new Student(1, "Julie"), 2 : new Student(2, "Robert")] 

// coerce map
println(map.asBoolean())

// set map as empty
map = [:]

// coerce map
println(map.asBoolean())

class Student{
   int rollNo
   String name

   Student(int rollNo, String name){
      this.rollNo = rollNo
      this.name = name
   }

   @Override
   public boolean equals(Object obj) {
      Student s = (Student)obj
      return this.rollNo == s.rollNo && this.name.equalsIgnoreCase(s.name)
   }
   
   @Override
   public String toString() {
      return "[ " + this.rollNo + ", " + this.name + " ]"
   }
}

Output

When we run the above program, we will get the following result −

true
false