Common Value Methods

Common value methods can be called on any Expr value: `none()`, numbers, strings, and objects.

They are mostly used for validation before a script performs numeric work, string parsing, or optional-value handling.

Checks whether the value is `none()`.

Example:

value = none();
 
if(value.is_none())
{
    print('missing value');
};

Checks whether the value is numeric NaN.

Only a numeric NaN value returns true.

Example:

value = nan();
 
value.is_nan();       // true

Checks whether the value is a number.

NaN is still a number, so `nan().is_num()` returns true.

Example:

(123).is_num();       // true
nan().is_num();       // true
'123'.is_num();       // false

Checks whether the value is a usable number and not NaN.

Use this before calculations that require a valid numeric value.

Example:

if(feed.is_num_notnan() && feed > 0)
{
    print('valid feed');
};

Checks whether the value is an integer numeric value.

Example:

(10).is_num_int();    // true
(10.5).is_num_int();  // false

Checks whether the value is a string.

Example:

'abc'.is_string();    // true
123.is_string();      // use (123).is_string() in real code

When calling a method on a numeric literal, use parentheses:

(123).is_string();    // false

Checks whether the value can be interpreted as a boolean value.

Finite numbers are boolean-compatible. Strings `true`, `false`, `1`, and `0` are also boolean-compatible.

Example:

(1).is_bool();        // true
'false'.is_bool();    // true
'abc'.is_bool();      // false

Previous: Built-in methods

Next: Number Methods