Question

我从第三方服务获得非常小的值，我需要将其转换为删除无用数字的数字。 `

<?php 
    $decimal = 50 
    //If value is 1.4E-45
    number_format($value, $decimal); 
    //output: 0.00000000000000000000000000000000000000000000140000 
    number_format($value, $decimal) +0 ;
    //output: 1.4E-45 
?>

`

示例输入::

1

输出1
1.00000000000000000000000000000000000000000000000000

输出：1
1.4E-45

输出：0.0000000000000000000000000000000000000000000014

正如您在代码中看到的，已经尝试添加0和number_format方法。

可以有两种方法

发现$ decimal值需要动态使用
始终传递$ decimal的最大可能值并删除无用的0。我们可以假设$ decimal的上限为50.

请建议php函数中的任何方法是否适用于任何方法

Answer 1

我推荐这种方法：

import thunk from 'redux-thunk';
import { persistStore } from 'redux-persist';
import { History, createBrowserHistory } from 'history';
import { createUserManager, loadUser } from "redux-oidc";
import { routerReducer, routerMiddleware } from 'react-router-redux';
import { createStore, applyMiddleware, compose, combineReducers, GenericStoreEnhancer, Store, StoreEnhancerStoreCreator, ReducersMapObject } from 'redux';

import * as StoreModule from './reducers';
import { ApplicationState, reducers } from './reducers';

import userManager from "./utils/userManager";

// Create browser history to use in the Redux store
const baseUrl = document.getElementsByTagName('base')[0].getAttribute('href')!;
const history = createBrowserHistory({ basename: baseUrl });

export default function configureStore(history: History, initialState?: ApplicationState) {
    // Build middleware. These are functions that can process the actions before they reach the store.
    const windowIfDefined = typeof window === 'undefined' ? null : window as any;
    // If devTools is installed, connect to it
    const devToolsExtension = windowIfDefined && windowIfDefined.__REDUX_DEVTOOLS_EXTENSION__ as () => GenericStoreEnhancer;


    const createStoreWithMiddleware = compose(
        applyMiddleware(thunk, routerMiddleware(history)),
        devToolsExtension ? devToolsExtension() : <S>(next: StoreEnhancerStoreCreator<S>) => next
    )(createStore);

    // Combine all reducers and instantiate the app-wide store instance
    const allReducers = buildRootReducer(reducers);
    const store = createStoreWithMiddleware(allReducers, initialState) as Store<ApplicationState>;
    loadUser(store, userManager);

    // Enable Webpack hot module replacement for reducers
    if (module.hot) {
        module.hot.accept('./reducers', () => {
            const nextRootReducer = require<typeof StoreModule>('./reducers');
            store.replaceReducer(buildRootReducer(nextRootReducer.reducers));
        });
    }
    const persistor = persistStore(store);
    return { store, persistor };
}

function buildRootReducer(allReducers: ReducersMapObject) {
    return combineReducers<ApplicationState>(Object.assign({}, allReducers, { routing: routerReducer }));
}

// Get the application-wide store instance, prepopulating with state from the server where available.
const initialState = (window as any).initialReduxState as ApplicationState;
export const { store, persistor } = configureStore(history, initialState);

如果您不注意边缘情况下的精确度损失并看到一些科学记数法，那么或者将您的字符串转换为浮动字符串。精心使用的rtrim可能是最好的方法。

Answer 2

您将小数设置为50，这就是它输出最后一个零的原因如果你计算$ decimals应该是什么，那么它应该给你你需要的东西。

ComponentTest

https://3v4l.org/fE1XD

它很漂亮，但它适用于此。

编辑：我有数字格式（$ value， 100 ）因为我需要确保将完整数字作为浮动值。
然后我使用preg_match来查找模式[0]以及你的数字在这个浮点数上的位置。

编辑2。这将向您展示为什么固定小数不是一个好的解决方案浮动数字不准确 https://3v4l.org/Ai0kE

PHP编号：将1.4E-N（N> 40）转换为十进制，删除无用的零位数

2 个答案: