从 javascript 中的字符串中删除最后一个 & 的干净方法

Question

Following is the code which is working fine for me, the only problem here I can see that I need to call slice(0, -1) on my string to remove & from the last. Let me know if there is a better and efficient way of writing this or this is also acceptable.

Thanks in advance.

Code -

 const object1 = { a: 'somestring', b: 42, c: '', d: "test1", e: null, f: 'test2' }; let str = ''; for (const [key, value] of Object.entries(object1)) { str += `${key}=${value}&` } const paramStr = str.slice(0, -1); console.log(paramStr);

Answer 1

I think doing the slice is fine. There are numerous other ways you could approach not having it. For example, you could map and then use .join('&') :

 const object1 = { a: 'somestring', b: 42, c: '', d: "test1", e: null, f: 'test2' }; console.log(Object.entries(object1).map(([k,v]) => `${k}=${v}`).join('&'))

Answer 2

Simply map and join , that will get rid of the trailing & :

let paramStr = Object.entries(object1).map(([key, value]) => key + "=" + value).join("&");

Demo:

 const object1 = { a: 'somestring', b: 42, c: '', d: "test1", e: null, f: 'test2' }; let paramStr = Object.entries(object1).map(([key, value]) => key + "=" + value).join("&"); console.log(paramStr);

Answer 3

If you are using lodash , you can consider utilizing the trimEnd function.

It can remove specified characters from the end of a string if you pass them as a second parameter.

For example:

 const paramStr = _.trimEnd('a=somestring&b=42&c=&d=test1&e=null&f=test2&', '&'); console.log(paramStr); // "a=somestring&b=42&c=&d=test1&e=null&f=test2"

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