一道面试题

在James Padolsey的博客里看到一篇面试题。

• Replace the string "The quick brown fox jumps over the lazy dog" with the string "The1 quick2 brown3 fox4 jumps5 over6 the7 lazy8 dog9".

自己写了几种方案：

var foo = "The quick brown fox jumps over the lazy dog";
var bar = "The1 quick2 brown3 fox4 jumps5 over6 the7 lazy8 dog9";

function test(func){
    var result = func(foo);
    console.log(result === bar ? true : result);
}

function custom1(str){
    var i = 0;
    return str.replace(/\w+/g, function(c){
        return c + ++i;
    })
}

function custom2(str){
    str = str.split(' ');
    for (var i = str.length; i--;){
        str[i] += i+1;
    }
    return str.join(' ');
}

function custom3(str){
    var i = 0;
    return str.replace(/(?=[\s]|$)/g, function(){
        return ++i;
    })
}

test(custom1);
test(custom2);
test(custom3);

但是没想到用Array的map方法，虽然这是javascript高版本才增加的。

"The quick brown fox jumps over the lazy dog".split(' ').map(function(w,i){ return w + (i + 1) }).join(' ')