javascript 如何向 console.log 添加变量？

How can I add a variable to console.log?

提问by Bradley McInerney

I'm making a simple game in JavaScript but in the story I need it to say the players name. so what I have so far is:

我正在用 JavaScript 制作一个简单的游戏，但在故事中我需要它说出玩家的名字。所以到目前为止我所拥有的是：

var name = prompt("what is your name?");

console.log("story" name "story);

how do I do the second line? or there is another way I could do this. Is it possible to have 2 console.log();on 1 line in the console?

我如何做第二行？或者有另一种方法可以做到这一点。console.log();控制台中是否可以在 1 行中设置2 ？

回答by Joseph

Then use +to combine strings:

然后用于+组合字符串：

console.log("story " + name + " story");

回答by Coin_op

console.logtakes multiple arguments, so just use:

console.log需要多个参数，所以只需使用：

console.log("story", name, "story");

If nameis an objector an arraythen using multiple arguments is better than concatenation. If you concatenate an objector arrayinto a string you simply log the type rather than the content of the variable.

如果name是 anobject或 an，array则使用多个参数比串联更好。如果您将一个objector连接array到一个字符串中，您只需记录类型而不是变量的内容。

But if nameis just a primitive type then multiple arguments works the same as concatenation.

但是如果name只是一个原始类型，那么多个参数的工作方式与连接相同。

回答by Sanjib Debnath

You can use another console method:

您可以使用另一种控制台方法：

let name = prompt("what is your name?");
console.log(`story ${name} story`);

回答by mannutech

There are several ways of consoling out the variable within a string.

有几种方法可以消除字符串中的变量。

Method 1 :

方法一：

console.log("story", name, "story");

Benefit : if name is a JSON object, it will not be printed as "story" [object Object] "story"

好处：如果 name 是一个 JSON 对象，它不会被打印为 "story" [object Object] "story"

Method 2 :

方法二：

console.log("story " + name + " story");

Method 3: When using ES6 as mentioned above

方法 3：当如上所述使用 ES6 时

console.log(`story ${name} story`);

Benefit: No need of extra , or +

好处：不需要额外的 , 或 +

Method 4:

方法四：

console.log('story %s story',name);

Benefit: the string becomes more readable.

好处：字符串变得更具可读性。

回答by EinArzt

When using ES6 you can also do this:

使用 ES6 时，您还可以这样做：

var name = prompt("what is your name?");
console.log(`story ${name} story`);

Note: You need to use backticks `` instead of "" or '' to do it like this.

注意：您需要使用反引号 `` 而不是 "" 或 '' 来做到这一点。

回答by Lyn Headley

You can pass multiple args to log:

您可以将多个参数传递给日志：

console.log("story", name, "story");

回答by Bluedog111

It depends on what you want.

这取决于你想要什么。

console.log("story "+name+" story")will concatenatethe strings together and print that. For me, I use this because it is easier to see what is going on.

console.log("story "+name+" story")将字符串连接在一起并打印出来。对我来说，我使用它是因为它更容易看到发生了什么。

Using console.log("story",name,"story")is similar to concatenation however, it seems to run something like this:

Usingconsole.log("story",name,"story")类似于 concatenation 但是，它似乎运行如下：

 var text = ["story", name, "story"];
 console.log(text.join(" "));

This is pushing all of the items in the array together, separated by a space: .join(" ")

这是将数组中的所有项目推到一起，用空格分隔： .join(" ")

回答by Gianfranco P.

%jworks for only Node.js. %jconverts a value to a JSON string and inserts it.

%j仅适用于 Node.js。%j将值转换为 JSON 字符串并插入。

console.log('%j new messages for', 7, 'john')
// 7 new messages for john

More string substitutions here:

更多字符串替换在这里：

• https://exploringjs.com/impatient-js/ch_console.html

• https://exploringjs.com/impatient-js/ch_console.html

Docs:

文档：

• Chrome: https://developers.google.com/web/tools/chrome-devtools/console/console-write#string_substitution_and_formatting
• Firefox: https://developer.mozilla.org/en-US/docs/Web/API/Console#Using_string_substitutions
• IE: https://docs.microsoft.com/en-gb/visualstudio/debugger/javascript-console-commands?view=vs-2019#ConsoleLog
• Node.js: https://docs.microsoft.com/en-gb/visualstudio/debugger/javascript-console-commands?view=vs-2019#ConsoleLog
• Spec: https://console.spec.whatwg.org/#formatter

• 铬：https: //developers.google.com/web/tools/chrome-devtools/console/console-write#string_substitution_and_formatting
• 火狐：https: //developer.mozilla.org/en-US/docs/Web/API/Console#Using_string_substitutions
• IE: https://docs.microsoft.com/en-gb/visualstudio/debugger/javascript-console-commands?view=vs-2019#ConsoleLog
• Node.js：https://docs.microsoft.com/en-gb/visualstudio/debugger/javascript-console-commands ?view =vs-2019#ConsoleLog
• 规范：https: //console.spec.whatwg.org/#formatter

回答by Sagar Kulkarni

Both console.log("story" + name + "story")and console.log("story", name, "story")works just fine as mentioned in earlier answers.

双方console.log("story" + name + "story")并console.log("story", name, "story")在前面的答案中提到的工作就好了。

I will still suggest of having a habit of console.log("story", name, "story"), because, if trying to print the object contents, like json object, having "story" + objectVariable + "story"will convert it into string.

我还是建议养成一个习惯console.log("story", name, "story")，因为，如果尝试打印对象内容，如json对象，拥有"story" + objectVariable + "story"会将其转换为字符串。

This will have output like : "story" [object Object] "story".

这将有输出，如："story" [object Object] "story"。

Just a good practice.

只是一个很好的做法。

回答by Ben Anderson

You can also use printf style of formatting arguments. It is available in at least Chrome, Firefox/Firebug and node.js.

您还可以使用 printf 样式的格式化参数。它至少在 Chrome、Firefox/Firebug 和 node.js 中可用。

var name = prompt("what is your name?");

console.log("story %s story", name);

It also supports %d for formatting numbers

它还支持 %d 格式化数字