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Several operators can be applied to objects of any type.

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as()

The

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as()

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operators coerces objects of one type to be an object of another. The target type is given as a string argument to the operator. The following types are available:

• "Array"
  

• "Boolean"
  

• "Map"
  

• "Null"
  

• "Number"
  

• "RegExp"

• "String"

The following coercions are valid:

• Strings can be coerced to numbers (null if not parsable) and regular expressions.
• Numbers can be coerced to strings.
• Regular expressions can be coerced to strings.
• Any expression can be coerced to Boolean.
• null and false can be coerced to 0,

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• and true can be coerced to 1

An error is thrown for other attempted coercions, unless the value being coerced by as() is already of the

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as()

The as() operators coerces objects of one type to be an object of another. The target type is given as a string argument to the operator. The following types are available in KRL:

• str. Coerce the target to have type string
• num. Coerce the target to have type number
• regexp. Coerce the target to have type regular expression
• trail. Coerce the target to have type trail

For example, the following constructs a string and then turns it into a regular expression that can be used by the replace() operator:

("re#q=" + q + "#i").as("regexpRegExp")

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• Strings can be coerced to numbers and regular expressions.
• Numbers can be coerced to strings.
• Regular expressions can be coerced to strings.
• Trails can be coerced to arrays.

defaultsTo()

The defaultsTo() operator returns the value of its first argument if the object is null. The second argument is a string and is optional. If present, it is written in the log if the object is null. 

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x = some_arr.filter(function(x){x == 5}).klog("Value after filter: ").head();

typeof()

The typeof() operator returns the type of the object to which it is applied. The return value is one of the strings that may be passed to as(). For example:

nums = [1, 2, 3]
nums_type = nums.typeof() // nums_type = "Array"

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