如何用JavaScript高阶函数实现map功能，问句形式？
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本文共计236个文字，预计阅读时间需要1分钟。
以下是对给定内容的简化
javascript/* map/reduce */'use strict';// 求积函数function product(arr) { return arr.reduce(function(x, y) { return x * y; });}// 将[1, 3, 5, 7, 9]变换成整数13579var arr=[1, 3, 5, 7, 9];product(arr);
gistfile1.txt/* map/reduce */ 'use strict'; //求积 function product(arr) { return arr.reduce( function(x,y){return x*y;}); } //把[1, 3, 5, 7, 9]变换成整数13579 var arr = [1, 3, 5, 7, 9]; arr.reduce(function (x, y) { return x * 10 + y; }); function string2int(s) { return Array.from(s).map(x=>x/1).reduce(function(x,y){return 10*x+y;}) //return s-0; } function normalize(arr) { } // parseInt is often used with one argument, but takes two. // The first is an expression and the second is the radix. // To the callback function, Array.prototype.map passes 3 arguments: // the element, the index, the array // The third argument is ignored by parseInt, but not the second one, // hence the possible confusion. ['1', '2', '3'].map( str => parseInt(str) ); // A simpler way to achieve the above, while avoiding the "gotcha": ['1', '2', '3'].map(Number); // [1, 2, 3] // but unlike `parseInt` will also return a float or (resolved) exponential notation: ['1.1', '2.2e2', '3e300'].map(Number); // [1.1, 220, 3e+300]
本文共计236个文字，预计阅读时间需要1分钟。
以下是对给定内容的简化
javascript/* map/reduce */'use strict';// 求积函数function product(arr) { return arr.reduce(function(x, y) { return x * y; });}// 将[1, 3, 5, 7, 9]变换成整数13579var arr=[1, 3, 5, 7, 9];product(arr);
gistfile1.txt/* map/reduce */ 'use strict'; //求积 function product(arr) { return arr.reduce( function(x,y){return x*y;}); } //把[1, 3, 5, 7, 9]变换成整数13579 var arr = [1, 3, 5, 7, 9]; arr.reduce(function (x, y) { return x * 10 + y; }); function string2int(s) { return Array.from(s).map(x=>x/1).reduce(function(x,y){return 10*x+y;}) //return s-0; } function normalize(arr) { } // parseInt is often used with one argument, but takes two. // The first is an expression and the second is the radix. // To the callback function, Array.prototype.map passes 3 arguments: // the element, the index, the array // The third argument is ignored by parseInt, but not the second one, // hence the possible confusion. ['1', '2', '3'].map( str => parseInt(str) ); // A simpler way to achieve the above, while avoiding the "gotcha": ['1', '2', '3'].map(Number); // [1, 2, 3] // but unlike `parseInt` will also return a float or (resolved) exponential notation: ['1.1', '2.2e2', '3e300'].map(Number); // [1.1, 220, 3e+300]