Question

我正在尝试创建一个包含随机数字的表格，如下所示：

<table>
  <tr>
    <td>123</td>
    <td>315</td>
    <td>356</td>
    <td>441</td>
  </tr>
  <tr>
    <td>664</td>
    <td>252</td>
    <td>236</td>
    <td>742</td>
  </tr>
...
<!-- more rows like the above -->
</table>

我的Html是：

<table>
  <tr ng-repeat="item in items">
    <td>{{randNumGen()}}</td>
    <td>{{randNumGen()}}</td>
    <td>{{randNumGen()}}</td>
  </tr>
</table>

我的JS是：

app.controller('TableCtrl', function($scope) {
  $scope.items = [1,2,3,4,5,6,7,8,9,0];
  $scope.randNumGen = function() {
    return Math.floor((Math.rand()*1000)+1);
  }
});

它返回所有随机数，就像我想要的那样，但它抛出一个JS错误说：

“错误：[$ rootScope：infdig]”

并且不会在此控制器下运行任何脚本。

Answer 1

randomNumGen()的结果是，在角度定义中是一个范围变量。如果它检测到对此函数结果的更改，则会触发摘要。由于结果几乎在所有情况下都不同，这将导致无限的摘要循环。

最好在摘要循环之前构建随机数组，然后将静态不变数组分配给范围，从而不会导致任何不需要/不需要的摘要循环。

一种方法是在加载控制器时构建一个简单的工厂来为您生成数组。然后输出它的内容。

angular.module('myapp', [])
    .factory('generator', function() {
        function buildRandArray(length) {
            var arr = [];

            for(var i = 0; i < (length || 10); i++) {
                var fill = [];
                for (var j = 0; j < 3; j++) {
                    fill.push(Math.floor((Math.random()*1000)+1));
                }
                arr.push(fill);
            }

            return arr;
        }

        return {
            buildRandArray : buildRandArray
        }
    })

    .controller('TableCtrl', function($scope, generator) {
        $scope.items = generator.buildRandArray(10);
    });

现在你的HTML将是

<table>
  <tr ng-repeat="item in items">
    <td ng-repeat="number in item">
        {{number}}
    </td>
  </tr>
</table>

Answer 2

检查出来

import pandas as pd
import re

df = pd.DataFrame(["BULL ESTOX 11X S", "BULL ESTOX X12 S"], columns=["name"])

description_map = {"ESTOX":"Euro STOXX 50"}
underlying_match = re.compile(r"\s(\S+)\s")
leverage_match = re.compile(r"\d+X|X\d+", flags=re.IGNORECASE)

def f(value):

    f1 = lambda x: description_map[underlying_match.findall(x)[0]] if underlying_match.findall(x)[0] in description_map else ""
    f2 = lambda x: leverage_match.findall(x)[0] if len(leverage_match.findall(x)) > 0 else ""
    f3 = lambda x: "-" if "BEAR" in x else "-" if "SHORT" in x else ""

    underlying = f1(value)
    leverage = f2(value)
    sign = f3(value)

    statement = "Tracks " + underlying

    if underlying == "":
        if sign == "-" and leverage == "":
            return statement + "{}".format("inversely.")
        if sign == "-" and leverage != "":
            return statement + "{} with {}{} leverage.".format("inversely", sign, leverage)
        if sign == "" and leverage != "":
            return statement + "with {}{} leverage.".format(sign, leverage)
        else:
            return "Tracks"

    if leverage[0].replace("X","x") == "x":
        leverage = ''.join(leverage[1:])+leverage[0].replace('X','x')

    if leverage != "" and sign == "-":
        statement += " {} with {}{} leverage.".format("inversely", sign, leverage)
    elif leverage != "" and sign == "":
        statement += " with {} leverage.".format(leverage)
    else:
        if sign == "-":
            statement += " {} ".format("inversely")

    return statement

df["description"] = df["name"].map(lambda x:f(x))

print df

我注意到Math.rand不是你的代码中的函数!!使用Math.random

Answer 3

不应该是Math.random()而不是Math.rand()吗？见reference on developer.mozilla.org

在ng-repeat中生成随机数

3 个答案: