To remove an element from a map:

Use the [map->remove] method. The following example removes the value for the key 'red' from the map leaving only the values for the keys 'blue' and 'green.'

Code

var (colours = map( 'red'='#ff0000',
                     'green' = '#00ff00',
                     'blue' = '#0000ff',
                     'grey' = '#aaaaaa') )

$colours->remove('red')

Result

map(blue = #0000ff, green = #00ff00, grey = #aaaaaa)