JavaScript中自带的 reduce()方法使用示例详解

[x1, x2, x3, x4].reduce(f) = f(f(f(x1, x2), x3), x4) 

'use strict';function string2int(s){if(!s){alert('the params empty');return;}if(s.length===1){return s*1;}var arr = [];for(var i=0; i<s.length; i++){arr.push(s.substr(i, 1)*1);}return arr.reduce(function(x, y){return x*10 + y;});}// 测试:if (string2int('0') === 0 && string2int('12345') === 12345 && string2int('12300') === 12300) {if (string2int.toString().indexOf('parseInt') !== -1) {alert('请勿使用parseInt()!');} else if (string2int.toString().indexOf('Number') !== -1) {alert('请勿使用Number()!');} else {alert('测试通过!');}}else {alert('测试失败!');}