使用Javascript中的变量格式化字符串模板 [英] Format string template with variables in Javascript

问题描述

我想使用静态定义的模板进行URL构建。

I want to use a statically defined template for URL building.

我正在尝试使用ES6字符串插值功能

I'm trying to use ES6 string interpolation feature for this

var template = "http://example.com/?name=${name}&age=${age}";

var name = "John";
var age = "30";

var url = `${template}`;

预期结果： http://example.com/?name=John&age=23

实际结果： http://example.com/?name= $ {name}& age = $ {age}

Actual result: http://example.com/?name=${name}&age=${age}

如果用字符串插值无法做到这一点，那么有比 String.prototype.replace 更好的方法吗？ / p>

In case this can't be done with string interpolation is there any better method than String.prototype.replace like

var url = template.replace(/\${name}/,"John").replace(/\${age}/, 23);

推荐答案

变量在评估时被替换文字，所以你不能创建一个可以在以后用变量替换的通用模板：

The variables are substituted at the moment of evaluation of the literal, so you can't create a universal template that can be substituted with variables later:

var template = `http://example.com/?name=${name}&age=${age}`;
var name = "John";
var age = "30";

console.log( template ); // "http://example.com/?name=undefined&age=undefined"

编辑：重复使用控制台会话并具有以前实验中定义的变量的人： https://jsfiddle.net/nwvcrryt /

fiddle for those who reuse a console session and have the variables defined from previous experiments: https://jsfiddle.net/nwvcrryt/

您也无法转换字符串文字我的名字是$ {name}到你想要做的模板。

You also can not convert a string literal "My name is ${name}" to a template like what you're trying to do.

但是，您可以使用一个取名字和年龄的函数并返回所需的网址：

You can, however, use a function that takes the name and age and returns the desired url:

const formatUrl = (name, age) => `http://example.com/?name=${name}&age=${age}`;
let name = "John";
let age = "30";
let url = formatUrl( name, age ); // "http://example.com/?name=John&age=30"

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