s = 'hello %s, how are you doing' % (my_name)
在python中就是这么做的。如何在javascript/node.js中做到这一点?
s = 'hello %s, how are you doing' % (my_name)
在python中就是这么做的。如何在javascript/node.js中做到这一点?
这样做:
s = 'hello ' + my_name + ', how are you doing'
更新
使用ES6,你也可以这样做:
s = `hello ${my_name}, how are you doing`
注意,从2015年开始,模板只使用反引号
https://stackoverflow.com/a/37245773/294884
let a = `hello ${name}` // NOTE!!!!!!!! ` not ' or "
注意,这是一个反引号,而不是引号。
如果你想要类似的东西,你可以创建一个函数:
function parse(str) {
var args = [].slice.call(arguments, 1),
i = 0;
return str.replace(/%s/g, () => args[i++]);
}
用法:
s = parse('hello %s, how are you doing', my_name);
这只是一个简单的示例,没有考虑不同类型的数据类型(如%i等)或%s的转义。但我希望这能给你们一些启发。我很确定也有库提供了类似的功能。
扩展String的几种方法。原型,或使用ES2015模板文字。
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>
如果使用node.js, console.log()将format string作为第一个参数:
console.log('count: %d', count);
跑龙套。格式可以做到这一点。
它将是v0.5.3的一部分,可以像这样使用:
var uri = util.format('http%s://%s%s',
(useSSL?'s':''), apiBase, path||'/');
在Node.js v4中,你可以使用ES6的Template字符串
var my_name = 'John';
var s = `hello ${my_name}, how are you doing`;
console.log(s); // prints hello John, how are you doing
你需要在'(反撇号)而不是'(撇号)内换行字符串
从node.js >4.0开始,它与ES6标准更加兼容,其中字符串操作得到了极大的改进。
原始问题的答案可以很简单:
var s = `hello ${my_name}, how are you doing`;
// note: tilt ` instead of single quote '
字符串可以展开多行,这使得模板或HTML/XML处理非常容易。关于它的更多细节和功能:模板字面量是在mozilla.org上的字符串字面量。
const格式=(…args) = > args.shift () .replace (/ % ([jsd]) / g, x = > x = = =“% j”?JSON.stringify(args.shift()): const name = 'Csaba' const格式化= format('Hi %s,今天是%s,您的数据是%j',名称,日期(),{数据:{国家:'匈牙利',城市:'布达佩斯'}}) console.log(格式化)
下面是Node.js中的一个多行字符串文本示例。
> 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
>
如果你使用的是ES6,你应该使用模板文字。
//you can do this
let sentence = `My name is ${ user.name }. Nice to meet you.`
点击此处阅读更多信息: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Template_literals
我写了一个函数来精确地解决这个问题。
第一个参数是要参数化的字符串。你应该把你的变量放在这个字符串中,就像这样“%s1, %s2,…”% s12”。
其他参数分别是该字符串的参数。
/***
* @example parameterizedString("my name is %s1 and surname is %s2", "John", "Doe");
* @return "my name is John and surname is Doe"
*
* @firstArgument {String} like "my name is %s1 and surname is %s2"
* @otherArguments {String | Number}
* @returns {String}
*/
const parameterizedString = (...args) => {
const str = args[0];
const params = args.filter((arg, index) => index !== 0);
if (!str) return "";
return str.replace(/%s[0-9]+/g, matchedStr => {
const variableIndex = matchedStr.replace("%s", "") - 1;
return params[variableIndex];
});
}
例子
parameterizedString("my name is %s1 and surname is %s2", "John", "Doe");
// returns "my name is John and surname is Doe"
parameterizedString("this%s1 %s2 %s3", " method", "sooo", "goood");
// returns "this method sooo goood"
如果变量位置在字符串中改变了,这个函数也支持它而不改变函数参数。
parameterizedString("i have %s2 %s1 and %s4 %s3.", "books", 5, "pencils", "6");
// returns "i have 5 books and 6 pencils."
var print = console.log;
function dformat(str, ...arr) {
return str.replace(/%(\d+)/g, function(_,i) {
return arr[--i];
});
}
function wformat(str, dict) {
return str.replace(/%(\w+)/g, function(_,k) {
return dict[k];
});
}
function sformat(str, dict) {
return str.replace(/\$(\w+)/g, function(_,m) {
return dict[m];
});
}
function tformat(str, dict) {
return str.replace(/\${(\w+)}/g, function(_,m) {
return dict[m];
});
}
print(1, dformat("uid:%1, name:%2", 120, "someone") )
print(2, wformat("color: %name", {name: "green"}) )
print(3, sformat("img: $url", {url: "#"}) )
print(4, tformat("${left} ${right}", {right:"1000", left: "7fff"}) )