A map function that can map over almost anything.
Execute a function
fn for each
Values returned from
fn are appended to an array which is
returned by the map function.
map(obj, fn, squash);
- obj - the object for which
fnwill be called for each
index. This can be an Array, Object, String, Number or whatever.
- fn - callback function which is called for each
index. Review the callback function section below.
- squash - when true, don't push undefined or null values on to the final array.
fn is called it is passed the following arguments:
- key - the
index, or attribute name from the object which is being mapped.
- value - the value of the current key, index or attribute.
- emit function - call this
functionpassing it a value to explicitly push a new value onto the final array.
- end function - call this
functionto stop iterating over
Any value returned from the callback function will be appended to the final array.
The only excpetion to this would be if
sqash is set to true in which case any
undefined or null return value would NOT be appended to the final array.
a = 405021;b = mapa//key is the index in the arrayif val > 10return val;;// b = [40, 50, null, null];//this time we will sqash falsy valuesc = mapa//key is the index in the arrayif val > 10return val;true; //turn on squash// c = [40, 50];//map over an object;d = customer_id : 1 name : 'Willy Wonka' ;e = mapdemitval;return key;;//e = [1, 'customer_id', 'Willy Wonka', 'name'];
These examples aren't that great. I typically use this function to map over arrays of objects that come from a database query.
Copyright (c) 2012 Daniel L. VerWeire
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