Being able to align text is really important when creating PDF file. The sample below is for setting text alignment during PDF generation  in JavaScript with BytescoutPDF.js (Bytescout PDF Generator for JavaScript).

// function that creates BytescoutPDF instance (defined in BytescoutPDF.js script which have to be included into the same page)
// then calls API methods and properties to create PDF document
// and returns created BytescoutPDF object instance
// this CreatePDF() function is called from Sample.html

function CreatePDF() {

    // create BytescoutPDF object instance
    var pdf = new BytescoutPDF();

    // set document properties: Title, subject, keywords, author name and creator name
    pdf.propertiesSet("Sample document title", "Sample subject", "keyword1, keyword 2, keyword3", "Document Author Name", "Document Creator Name");

    // add new page

    // set text box
    pdf.textSetBox(50, 50, 500, 500);
    // and draw a rectangle around it
    pdf.graphicsDrawRectangle(50, 50, 500, 500);

    // add aligned text:

    pdf.textAddToBox('Left aligned text', true);

    pdf.textAddToBox('Center aligned text', true);

    pdf.textAddToBox('Right aligned text', true);

    pdf.textAddToBox('Justfied text Justfied text Justfied text Justfied text Justfied text Justfied text Justfied text Justfied text', true);

    // return BytescoutPDF object instance
    return pdf;

Generated PDF file with different text alignments (click to view full size):

Click to view full size