Question

const temp = [27, 28, 30, 40, 42, 35, 30]; let high = temp.findLast(x => x > 40); actually I am self learning through W3School and the above code specially second line with (x => x > 40); is difficult to understand at this stage. May be it elaborate later in next chapters, So please can anyone tell me what it is? And how it works?

我没有尝试过。我正在学习,我有粗略的想法,那就是,它是一种arrow的 function!

Answer 1

法典:

const temp = [27, 28, 30, 40, 42, 35, 30];
let high = temp.findLast(x => x > 40);

页: 1 每个要素中包含7项内容,其类型数值为:
In the second line there is the creation of a variable that will later receive a single number that is the result of the following code sentence temp.findLast(x => x > 40);
temp.findLast() will traverse the temp array in reverse order (starting from 30, 35... up to 27) and will return the first element tested that satisfy the true condition of the callback x => x > 40 passed by parameter;

a) 如果在阵列开始时增加一个价值45的元件,你就会看到,<代码>高将保持42个,因为有42个是“顶”()”第1个元件,由“呼号”回来。

b) The iteration of the findLast function is interrupted as soon as it receives the first number greater than or equal to 40 in reverse order, that is, there will no longer be any processing resources being used;

c) 如无<代码>true > 状况由questback退回,这意味着find Last(x =>x > 40)将完全通过<代码>temp阵列,并将返回un specified。页: 1

文件:https://developer.mozilla.org/en-US/docs/Web/Java/Reference/Global_Objects/Array/findLast

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