Mr.Array

Mr.Array is a JavaScript Array Object method extention library. It will help you operate every item in array in LINQ way. And at the same time, the static method invoke is accepted.

Supported APIs

• select

var source = [{ id : 1, month : 11 }, { id : 2, month : 12 }, { id : 3, month : 13  }];
var idResult = source.select(function(o){ return o.id; });

• selectMany

var source = [{ a : [1,2,3]}, { a : [4,5,6] }, { a : [7,8,9] }];
var result = source.selectMany(function(o){ return o.a; });

• toDictionary

var source = [{ name : 'a',  value : [1,2,3] }, { name : 'b',  value : [4,5,6] }, { name : 'c',  value : [7,8,9] }, { name : 'a', value : [10, 11, 12] }];
var result = 
    source.toDictionary(function(obj){
		return obj.name + '_group';
	}, function(obj){
		return obj.value[0];
	});

• where

var source = [{ id : 1, month : 11 }, { id : 2, month : 12 }, { id : 3, month : 13  }];
var idResult = source.where(function(o){ return o.id > 2; });

• orderBy

var source = [2, 5, 6, 1, 7, 8, 9, 3, 10, 4];
var result = source.orderBy(function(a,b){ return a - b });

• groupBy

var source = [{ name : 'Attach'}, { name : 'Charactor'}, { name : 'Bee'}, { name : 'Cycle'}, { name : 'Add'}];
var result = 
    source
	.orderBy(function(a, b){ return a.name.charCodeAt(0) - b.name.charCodeAt(0); })
	.groupBy(function(obj){ return obj.name.charAt(0); });

• any

var source = [{ name : 'Attach' }, { name : 'Charactor' }, { name : 'Bee' }, { name : 'Cycle' }, { name : 'Add' }];
var result = 
    source.
	any(function(obj){ return obj.name.charAt(0) == 'B'; });

• all

var source = [{ name : 'Attach' }, { name : 'Charactor' }, { name : 'Bee' }, { name : 'Cycle' }, { name : 'Add' }];
var result = source.all(function(obj){
    return obj.name.length > 3; 
});

• take

var source = [2, 5, 6, 1, 7, 8, 9, 3, 10, 4];
var result = source.take(3);

• skip

var source = [2, 5, 6, 1, 7, 8, 9, 3, 10, 4];
var result = source.skip(5);

• each

var source = [2, 5, 6, 1, 7, 8, 9, 3, 10, 4], i = 0;
source.each(function(val, idx){
    equal(i++, idx);
    equal(source[idx], val);
});

• reduce_rtl

var source = [2, 5, 6, 1, 7, 8, 9, 3, 10, 4], i = 8;
var result = source.reduce_rtl(function(curr, old, idx, array){
    return curr + old;
});

• reduce_ltr

var source = [2, 5, 6, 1, 7, 8, 9, 3, 10, 4], i = 1;
var result = source.reduce_ltr(function(curr, old, idx, array){	
    return curr + old;
});

• except

var source = [{ a : 1, b : 22 }, { a : 2, b : 77 }, { a : 2, b : 2 }, { a : 3, b : 5 }];
var source2 = [{ a : 1, b : 11 }, { a : 2, b : 32 }, { a : 3, b : 30 }, { a : 4, b : 2 }];
var result = source.except(source2, function(curr){ return curr.a == 1 || curr.a == 2; });

• intersect

var source = [{ a : 1, b : 10 }, { a : 1, b : 10 }, { a : 2, b : 30 }, { a : 1, b : 40 }];
var source2 = [{ a : 1, b : 10 }, { a : 4, b : 20 }, { a : 2, b : 0 }, ];
var result = source.intersect(source2, function(curr, compare){ return curr.a == 1 && curr.b == 10 });

• union

var source = [2, 2, 4, 4, 8], source2 = [9, 3, 9, 3];
var result = source.union(source2);

• diff

var source = [2, 2, 1, 10, 3, 9, 4];
var source2 = [1, 10, 20, 4];
var result = source.diff(source2);

• contains
• containsAll
• distinct

var source = [2, 2, 4, 4, 8, 9, 3, 9, 3];
var result = source.distinct();

Example: Group programming languages

// 2011年排行
var langs = [
    'Java', 'C', 'C++', 'C#', 'PHP', 'Python', 'Visual Basic', 'Objective-C', 'Perl', 'JavaScript',
    'Ruby', 'Assembly*', 'Delphi', 'Go', 'Lisp', 'Lua', 'Ada', 'Pascal', 'NXT-G', 'Scheme*',
    'RPG(OS/40)', 'Visual Basic .NET', 'Transact-SQL', 'R', 'Groovy', 'SAS', 'MATLAB', 'ABAP', 'Scratch', 'PL/SQL',
    'Haskell', 'Logo', 'D', 'Object Pascal', 'Fortran', 'Alice', 'Forth', 'COBOL', 'Erlang', 'Bash', 
    'ML', 'MAD', 'APL', 'Scala', 'F#', 'ActionScript', 'Smalltalk', 'C Shell', 'CL(OS/400)', 'Prolog'
];

var result = 
    langs
	.orderBy(function(a, b){ return a.charCodeAt(0) - b.charCodeAt(0); }) // important !!
	.groupBy(function(name){ return name.charAt(0); })
	.select(function(group){
		var obj = {};
		obj[group[0].charAt(0)] = group.orderBy(function(a, b){ return a.length - b.length; });
		return obj;
	});