bool

Returns a bool from a specified value. If no value is given, false is returned.

Types with a length evaluate to true when the length is not 0, and false otherwise.

This function does not generate a change.

Function

bool(value)

Arguments

Return value

A boolean value.

Example

This code shows some return values for bool():

[
    "false:",
    { bool();                       /* default bool is false                        */},
    { bool(0);                      /* zero (0) evaluates to false                  */},
    { bool(0.0);                    /* zero float (0.0) evaluates to false          */},
    { bool(nil);                    /* nil evaluates to false                       */},
    { bool({});                     /* an empty thing evaluates to false            */},
    { bool(err());                  /* all errors evaluate to false                 */},
    { bool('');                     /* an empty string evaluates to false           */},
    { bool([]);                     /* an empty array evaluates to false            */},
    { bool(set());                  /* an empty set evaluates to false              */},
    { bool(room());                 /* a non-stored room (no Id) evaluates to false */},
    { bool({
        t = task(datetime(), ||0);
        t.cancel();
        t;
    });                             /* non-scheduled tasks evaluate to false        */},

    "true:",
    { bool(42);                     /* non zero integers evaluates to true          */},
    { bool(-1.0);                   /* non zero float values evaluates to true      */},
    { bool({answer: 42});           /* non empty thing evaluates to true            */},
    { bool([1, 2, 3]);              /* non empty array evaluates to true            */},
    { bool('forty two');            /* non empty string evaluates to true           */},
    { bool(set({}, {}));            /* non empty set evaluates to true              */},
    { bool(.room = room());         /* a stored room (with Id) evaluates to true    */},
    { bool(future(||nil));          /* futures evaluate to true                     */},
    { bool(timeval(0));             /* datetime and timeval always evaluate to true */},
    { bool(task(datetime(), ||0));  /* scheduled tasks evaluate to true             */},
];

Return value in JSON format

[
    "false:",
    false,
    false,
    false,
    false,
    false,
    false,
    false,
    false,
    false,
    false,
    false,
    "true:",
    true,
    true,
    true,
    true,
    true,
    true,
    true,
    true,
    true,
    true
]