如何將變量放入JavaScript字符串中？ （Node.js）

Question

s = 'hello %s, how are you doing' % (my_name) 

這就是你如何在python中做到這一點。你怎麼能在javascript/node.js中做到這一點？

Answer 1

如果你想有類似的東西，你可以創建一個功能：

function parse(str) { 
    var args = [].slice.call(arguments, 1), 
     i = 0; 

    return str.replace(/%s/g, function() { 
     return args[i++]; 
    }); 
} 

用法：

s = parse('hello %s, how are you doing', my_name); 

這僅僅是一個簡單的例子，並沒有考慮到不同nt種數據類型（如%i等）或轉義%s。但我希望如果給你一些想法。我很確定也有庫提供這樣的功能。

Answer 2

做那

s = 'hello ' + my_name + ', how are you doing' 

Answer 3

var user = "your name"; 
var s = 'hello ' + user + ', how are you doing'; 

Answer 4

嘗試sprintf in JS 或者你可以使用這個gist

Answer 5

一些方法來擴展String.prototype，或者使用ES2015 template literals。

var result = document.querySelector('#result'); 
 
// ----------------------------------------------------------------------------------- 
 
// Classic 
 
String.prototype.format = String.prototype.format || 
 
    function() { 
 
    var args = Array.prototype.slice.call(arguments); 
 
    var replacer = function (a){return args[a.substr(1)-1];}; 
 
    return this.replace(/(\$\d+)/gm, replacer) 
 
}; 
 
result.textContent = 
 
    'hello $1, $2'.format('[world]', '[how are you?]'); 
 

 
// ES2015#1 
 
'use strict' 
 
String.prototype.format2 = String.prototype.format2 || 
 
    function(...merge) { return this.replace(/\$\d+/g, r => merge[r.slice(1)-1]); }; 
 
result.textContent += '\nHi there $1, $2'.format2('[sir]', '[I\'m fine, thnx]'); 
 

 
// ES2015#2: template literal 
 
var merge = ['[good]', '[know]']; 
 
result.textContent += `\nOk, ${merge[0]} to ${merge[1]}`;

<pre id="result"></pre>

Answer 6

如果您正在使用的node.js，console.log()採用格式字符串作爲第一個參數：

console.log('count: %d', count); 

Answer 7

util.format做到這一點。

這將是v0.5.3一部分，可以這樣使用：

var uri = util.format('http%s://%s%s', 
     (useSSL?'s':''), apiBase, path||'/'); 

Answer 8

隨着Node.js的v4，您可以使用ES6的Template strings

var my_name = 'John'; 
var s = `hello ${my_name}, how are you doing`; 
console.log(s); // prints hello John, how are you doing 

你需要反引號`內包串 而不是'

Answer 9

從node.js>4.0它與ES6標準更加兼容，其中字符串操作大大改進。

var s = `hello ${my_name}, how are you doing`; 
// note: tilt ` instead of single quote ' 

凡字符串可以傳播多條線路，它使模板或HTML/XML的過程很簡單：作爲

的答案原來的問題可以很簡單。關於它的更多細節和更多功能：Template literals are string literals at mozilla.org。

Answer 10

const format = (...args) => args.shift().replace(/%([jsd])/g, x => x === '%j' ? JSON.stringify(args.shift()) : args.shift()) 
 

 
const name = 'Csaba' 
 
const formatted = format('Hi %s, today is %s and your data is %j', name, Date(), {data: {country: 'Hungary', city: 'Budapest'}}) 
 

 
console.log(formatted)

Answer 11

以下是在一個節點多行字符串文字例子。JS。

> let name = 'Fred' 
> tm = `Dear ${name}, 
... This is to inform you, ${name}, that you are 
... IN VIOLATION of Penal Code 64.302-4. 
... Surrender yourself IMMEDIATELY! 
... THIS MEANS YOU, ${name}!!! 
... 
... ` 
'Dear Fred,\nThis is to inform you, Fred, that you are\nIN VIOLATION of Penal Code 64.302-4.\nSurrender yourself IMMEDIATELY!\nTHIS MEANS YOU, Fred!!!\n\n' 
console.log(tm) 
Dear Fred, 
This is to inform you, Fred, that you are 
IN VIOLATION of Penal Code 64.302-4. 
Surrender yourself IMMEDIATELY! 
THIS MEANS YOU, Fred!!! 


undefined 
> 

Answer 12

如果您使用的是ES6，則應使用模板文字。

//you can do this 
let sentence = `My name is ${ user.name }. Nice to meet you.` 

在這裏閱讀更多： https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Template_literals