比较JS合并数组的各种方法及其优劣

标签：数组   合并   拼接   slice   reduce   

var q = [ 5, 5, 1, 9, 9, 6, 4, 5, 8];
var b = [ "tie", "mao", "csdn", "ren", "fu", "fei" ];

[
    5, 5, 1, 9, 9, 6, 4, 5, 8, 
    "tie", "mao", "csdn", "ren", "fu", "fei"
]

var c = q.concat( b );

q; // [5,5,1,9,9,6,4,5,8]
b; // ["tie","mao","csdn","ren","fu","fei"];

c; // [5,5,1,9,9,6,4,5,8,"tie","mao","csdn","ren","fu","fei"]

q = b = null; // `q` and `b` 现在可以被垃圾回收了

// 将数组 `b` 插入 `q`
for (var i=0; i < b.length; i++) {
    q.push( b[i] );
}

q; // [5,5,1,9,9,6,4,5,8,"tie","mao","csdn","ren","fu","fei"]

b = null;

// `q` into `b`:
for (var i=q.length-1; i >= 0; i--) {
    b.unshift( q[i] );
}

b; // [5,5,1,9,9,6,4,5,8,"tie","mao","csdn","ren","fu","fei"]

q = null;

// `b` onto `q`:
q = b.reduce( function(coll,item){
    coll.push( item );
    return coll;
}, q );

q; // [5,5,1,9,9,6,4,5,8,"tie","mao","csdn","ren","fu","fei"]

// or `q` into `b`:
b = q.reduceRight( function(coll,item){
    coll.unshift( item );
    return coll;
}, b );

b; // [5,5,1,9,9,6,4,5,8,"tie","mao","csdn","ren","fu","fei"]

// `b` onto `q`:
q.push.apply( q, b );

q; // [5,5,1,9,9,6,4,5,8,"tie","mao","csdn","ren","fu","fei"]

// or `q` into `b`:
b.unshift.apply( b, q );

b; // [5,5,1,9,9,6,4,5,8,"tie","mao","csdn","ren","fu","fei"]

function combineInto(q,b) {
    var len = q.length;
    for (var i=0; i < len; i=i+5000) {
        // 一次处理5000条
        b.unshift.apply( b, q.slice( i, i+5000 ) );
    }
}

比较JS合并数组的各种方法及其优劣

标签：数组   合并   拼接   slice   reduce   

原文地址：http://blog.csdn.net/renfufei/article/details/39376311