JS.hasValue Function

Format

Description

The JS.hasValue function returns whether a JavaScript variable or property is defined (not undefined).

The string expression name is evaluated and can refer to a variable in CSPro's JavaScript global execution context or an object's property if the object exists globally. For example, the following values can be specified as a name:

myFunction
globalThis.myFunction
myObject.myProperty
myObject['my' + 'Property']

Return Value

The function returns a logical value of 1 (true) if the variable or property is defined, and 0 (false) if undefined. If the JavaScript evaluation ends in an uncaught exception, the exception's message is suppressed (unlike other functions in the JS namespace) and the function returns false.

Example (Variables)

JS.hasValue("csproVersion"); // 0
JS.setValue("csproVersion", 8.1);
JS.hasValue("csproVersion"); // 1
JS.eval("csproVersion = undefined;");
JS.hasValue("csproVersion"); // 0

Example (Object Properties)

JS.setValueFromJson("france", ' { "name": "France", '
' "capital": "Paris", '
' "currency": "Euro", '
' "republicNumber": 5, '
' "languages": ["French"] }');

JS.hasValue("france"); // 1
JS.hasValue("globalThis.france"); // 1
JS.hasValue("france.capital"); // 1
JS.hasValue("france['CAPITAL']"); // 0
JS.hasValue("france['CAPITAL'.toLowerCase()]"); // 1
JS.hasValue("france.languages[0]"); // 1
JS.hasValue("france.languages[1]"); // 0
JS.hasValue("france[throw new Error()]") // 0