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jQuery.map to iterate over objects with a .length property

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This commit is contained in:
Dan Heberden 2011-03-21 12:12:31 -07:00
parent e38f074d14
commit d832f4f71e
2 changed files with 27 additions and 25 deletions
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40
src/core.js
View file

@ -704,33 +704,33 @@ jQuery.extend({
return ret; return ret;
}, },
// arg is for internal usage only // arg is for internal usage only
map: function( elems, callback, arg ) { map: function( elems, callback, arg ) {
var ret = [], value, i = 0, var value, ret = [],
length = elems.length, i = 0,
// same object detection used in jQuery.each, not full-proof but very speedy. length = elems.length,
isObj = length === undefined; // process .length if it's just an object member
isArray = length !== undefined && ( elems[ length - 1 ] || jQuery.isArray( elems ) );
// the work for the loops - run elems[x] through callback
inLoop = function( key ) { // Go through the array, translating each of the items to their
value = callback( elems[ key ], key, arg ); // new value (or values).
if ( isArray ) {
for ( ; i < length; i++ ) {
value = callback( elems[ i ], i, arg );
if ( value != null ) { if ( value != null ) {
ret[ ret.length ] = value; ret[ ret.length ] = value;
} }
} }
// Go thorugh every key on the object // Go thorugh every key on the object,
if ( isObj ) { } else {
for ( key in elems ) { for ( key in elems ) {
inLoop( key ); value = callback( elems[ key ], key, arg );
}
if ( value != null ) {
// Go through the array, translating each of the items to their ret[ ret.length ] = value;
// new value (or values). }
} else {
for ( ; i < length; i++ ) {
inLoop( i );
} }
} }

12
test/unit/core.js
View file

@ -608,7 +608,7 @@ test("first()/last()", function() {
}); });
test("map()", function() { test("map()", function() {
expect(6); expect(7);
same( same(
jQuery("#ap").map(function(){ jQuery("#ap").map(function(){
@ -630,26 +630,28 @@ test("map()", function() {
var keys = jQuery.map( {a:1,b:2}, function( v, k ){ var keys = jQuery.map( {a:1,b:2}, function( v, k ){
return k; return k;
}); });
equals( keys.join(""), "ab", "Map the keys from a hash to an array" ); equals( keys.join(""), "ab", "Map the keys from a hash to an array" );
var values = jQuery.map( {a:1,b:2}, function( v, k ){ var values = jQuery.map( {a:1,b:2}, function( v, k ){
return v; return v;
}); });
equals( values.join(""), "12", "Map the values from a hash to an array" ); equals( values.join(""), "12", "Map the values from a hash to an array" );
// object with length prop
var values = jQuery.map( {a:1,b:2, length:3}, function( v, k ){
return v;
});
equals( values.join(""), "123", "Map the values from a hash with a length property to an array" );
var scripts = document.getElementsByTagName("script"); var scripts = document.getElementsByTagName("script");
var mapped = jQuery.map( scripts, function( v, k ){ var mapped = jQuery.map( scripts, function( v, k ){
return v; return v;
}); });
equals( mapped.length, scripts.length, "Map an array(-like) to a hash" ); equals( mapped.length, scripts.length, "Map an array(-like) to a hash" );
var flat = jQuery.map( Array(4), function( v, k ){ var flat = jQuery.map( Array(4), function( v, k ){
return k % 2 ? k : [k,k,k];//try mixing array and regular returns return k % 2 ? k : [k,k,k];//try mixing array and regular returns
}); });
equals( flat.join(""), "00012223", "try the new flatten technique(#2616)" ); equals( flat.join(""), "00012223", "try the new flatten technique(#2616)" );
}); });