pm.sendRequest is working after the for loop iteration is completed even though the request is inside the loop

Help
#1

I’m trying to trigger a “pm.sendRequest” inside a for loop and the request is getting sent only after the iteration is completed, though I have kept the request inside the loop.

My Test look like,

for (i=0;i<5;i++)
{
    const requestObject = {
    url: 'https://reqres.in/api/users?page=2',
    method: 'GET',
    header: 'Content-Type:application/json',

}
        console.log(i)
pm.sendRequest(requestObject, (err, res) => {
        console.log(i)

})}

The "i" which is getting printed inside the pm.sendRequest is alwas printed as 5.

Could you please help me in resolving this issue.
#2

Hi @VasanthPasupathi! Welcome to the community :tada:

Using Postman Echo as an example, the following worked for me.

for (var i=0; i<5; i++) {

    const reqObj = {
        'url': `https://postman-echo.com/get?foo=${i}`,
        'method': 'GET'
    }
    pm.sendRequest(reqObj, (err, res) => {
        if (err) {
            console.log(err)
        } else {
            console.log(res.json().args.foo)
        }
    })
    console.log(i)
}

This returns:
Screen Shot 2021-02-08 at 4.26.21 pm

Hope this helps!
Let me know if you have further questions!

#3

Hi @taehoshino ,
The iteration is not running proper if you could see your screenshot the iteration is 0,1,3,2,4 and not 0,1,2,3,4.

Also I want the I to be printed inside the if or else block if you try doing that you’ll be getting only the last value of ‘i’ printed

#4

I know what you mean :+1:
That’s because the pm.sendRequest is asynchronous function and by the time res is returned from pm.sendRequest call, the value of i is already proceeded to the last value.

If you want to show value of i corresponding to each request, you can use Promise, e.g.:

const sendReq = (i) => {
    const reqObj = {
        'url': `https://postman-echo.com/get?foo=${i}`,
        'method': 'GET'
    }
    return new Promise((resolve, reject) => {
        pm.sendRequest(reqObj, (err, res) => {
            if (err) {
                reject(err)
            } else {
                resolve(i)
            }
        })
    })
}

for (var i=0; i<5; i++) {
    sendReq(i).then((res) => {
        console.log(res)
    })
}

But again, console.log(res) in for loop is only printed after the response is returned, so it is not necessarily the numerical order.

Hope this clarifies a bit :upside_down_face: