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Thread: convert Qstring into int

  1. #1
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    Post convert Qstring into int

    Sir ,
    i have a Qstring (10 digit number suppose that ex. 9990540087) i want convert in integer but we find zero .
    source code:
    Qstring str ;
    str=ui->lineEdit->text();
    int n;
    n=str.toInt();
    we r find o, please help me how to convert this type of string in integer.

  2. #2

    Default Re: convert Qstring into int

    Hi sabbu,

    You can try it :

    Qt Code:
    1. bool convertOK;
    2. unsigned long int n = ui->lineEdit()->text().toULong(&convertOK);
    3. if(!convertOK) return -1;
    To copy to clipboard, switch view to plain text mode 


  3. #3
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    Default Re: convert Qstring into int

    A 32bit (which is probably what you use) unsigned int can only store values till 4.294.967.295. So you should use a long or something that can handle such large numbers.

  4. #4
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    Default Re: convert Qstring into int

    You can try this -
    Qt Code:
    1. bool ok;
    2. QString str = "9990540087";
    3. long no = sss.toLong(&ok,10);
    To copy to clipboard, switch view to plain text mode 

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    Default Re: convert Qstring into int

    let me guess, you are working on a 64bit system. To ensure, that your code is working everywhere one probably should use q(u)int64.

    EDIT: Eh, you should stay with the thread starters number! 1234567809 != 9990540087 and 1234567809 is small enough to get into a 32 bit signed integer!

  6. #6
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    Default Re: convert Qstring into int

    yes i am using 64 bit system
    Qt Code:
    1. bool ok;
    2. QString str = "9990540087";
    3. quint64 no = str.toLong(&ok,10);
    To copy to clipboard, switch view to plain text mode 

    it is working fine.

  7. #7
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    Default Re: convert Qstring into int

    sir,
    i could not success i am tired.My operting system is 32 bit. when i convert a string 10 digit number find only 0 .if i convert string 9 digit number i find 9 digit .i use all below code but i am not success.please help me
    1.bool ok;
    2.QString str = "9990540087";
    3.quint64 no = str.toLong(&ok,10);
    ///////////////////////////////////
    1.bool convertOK;
    2.unsigned long int n = ui->lineEdit()->text().toULong(&convertOK);
    3.if(!convertOK) return -1;
    //////////////
    1. bool ok;
    2.QString str = "9990540087";
    3.long no = sss.toLong(&ok,10);

  8. #8
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    Default Re: convert Qstring into int

    Use this, you need 64 bit number, with 32 bit unsigned you get a max of 4294967295, but you use number larger than this.

    Qt Code:
    1. QString str("9990540087");
    2. quint64 number = str.toULongLong();
    3. or
    4. qulonglong number = str.toULongLong();
    5. //or even str.toLongLong() signed version will also work for a typical 10-digit number
    To copy to clipboard, switch view to plain text mode 
    Last edited by Santosh Reddy; 8th June 2011 at 08:16.

  9. The following user says thank you to Santosh Reddy for this useful post:

    solook (17th September 2012)

  10. #9
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    Default Re: convert Qstring into int

    Thanks ,
    this code is work for me.

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