JavaScript for循环替代方案:repeat(n，function(i){...}); [英] JavaScript for-loop alternative: repeat(n, function(i) { ... });

问题描述

这是常规的for循环:

This is the regular for-loop:

for (var i = 0; i < n; i++) { ... }

它用于遍历数组，但也只是重复执行某些过程n次.

It is used to iterate over arrays, but also to just repeat some process n times.

我使用上述表格，但它使我感到排斥.标头var i = 0; i < n; i++很丑陋，每次使用时都必须按字面意义进行重写.

I use the above mentioned form, but it repulses me. The header var i = 0; i < n; i++ is plain ugly and has to be rewritten literally every time it is used.

我写这个问题是因为我想出了一个替代方案:

I am writing this question because I came up with an alternative:

repeat(n, function(i) { ... });

这里我们使用repeat函数，该函数带有两个参数:
1.迭代次数，
2.主体代表正在重复的过程的功能.

Here we use the repeat function which takes two arguments:
1. the number of iterations,
2. a function which body represents the process that is being repeated.

隐藏代码"如下所示:

function repeat(n, f) {
    for (var i = 0; i < n; i++) {
        f(i);
    }
} 

(我知道在流程的范围链中具有两个额外的级别"会对性能产生影响)

(I am aware of the performance implications of having two additional "levels" in the scope chain of the process)

顺便说一句，对于那些使用jQuery库的人来说，上述功能可以通过$.each方法立即实现，如下所示:

BTW, for those of you who use the jQuery library, the above mentioned functionality can be achieved out-of-the-box via the $.each method like so:

$.each(Array(n), function(i) { ... });  

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那您怎么看?此repeat函数是否是本机for循环的有效替代方法?这种选择的弊端是什么(除了性能-我对此有所了解)?

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So what do you think? Is this repeat function a valid alternative to the native for loop? What are the down-sides of this alternative (other than performance - I know about that)?

母语:

for (var i = 0; i < 10; i++) {
    // do stuff
}

替代:

repeat(10, function(i) {
    // do stuff
});

推荐答案

这是一个有趣的想法，但是如果您不喜欢该循环的语法，则总是可以执行另一种类型的循环:

it's an interesting thought, but if you dislike the syntax for the loop, you could always do a different type of loop:

var i = arr.length; 
while (i--) {
    // do stuff
}

相反的while循环通常也比for循环快.

the reverse while loop is generally faster than a for loop as well.

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