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Phone API Reference - Extended - util.isUndef

Phone API Reference - Extended - util.isUndef

Desk Phone API features described in this section are deprecated and supported only on the following models: D40, d45, d50, d60, d62, d65, d70

util.isUndef

Description

Returns true if the supplied variable is undefined, false if it is defined.

Basic Example: 

util.isUndef(var);

Note: if the variable you are testing has not been declared in anyway, this will throw an exception. If it has been declared but iniitalized as undefined (e.g,. not set in any way), the code with process.

Parameters

Name

Required

Type

Default

Description

Name

Required

Type

Default

Description

var

Yes

variable

 

Variable to be checked for definition.

 

Examples

util.isUndef returns true or false

var declaredUndef; var str = 'foo'; var obj = {'test1' : 'abc'}; util.isUndef(str);  // returns false util.isUndef(obj.test1);    // returns false util.isUndef(obj.test2);    // returns true util.isUndef(declaredUndef); // true util.isUndef(nonDeclaredVariable); // throws exception

 

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