Vendor/phpspreadsheet/phpoffice/phpspreadsheet/src/PhpSpreadsheet/Worksheet/Worksheet.php
public function setTitle($pValue, $updateFormulaCellReferences = true, $validate = true)
    {
        // Is this a 'rename' or not?
        if ($this->getTitle() == $pValue) {
            return $this;
        }

        // Old title
        $oldTitle = $this->getTitle();

        if ($validate) {
            // Syntax check
            self::checkSheetTitle($pValue);

            if ($this->parent) {
                // Is there already such sheet name?
                if ($this->parent->sheetNameExists($pValue)) {
                    // Use name, but append with lowest possible integer

                    if (Shared\StringHelper::countCharacters($pValue) > 29) {
                        $pValue = Shared\StringHelper::substring($pValue, 0, 29);
                    }
                    $i = 1;
                    while ($this->parent->sheetNameExists($pValue . ' ' . $i)) {
                        ++$i;
                        if ($i == 10) {
                            if (Shared\StringHelper::countCharacters($pValue) > 28) {
                                $pValue = Shared\StringHelper::substring($pValue, 0, 28);
                            }
                        } elseif ($i == 100) {
                            if (Shared\StringHelper::countCharacters($pValue) > 27) {
                                $pValue = Shared\StringHelper::substring($pValue, 0, 27);
                            }
                        }
                    }

                    $pValue .= " $i";
                }
            }
        }

        // Set title
        $this->title = $pValue;
        $this->dirty = true;

        if ($this->parent && $this->parent->getCalculationEngine()) {
            // New title
            $newTitle = $this->getTitle();
            $this->parent->getCalculationEngine()
                ->renameCalculationCacheForWorksheet($oldTitle, $newTitle);
            if ($updateFormulaCellReferences) {
                ReferenceHelper::getInstance()->updateNamedFormulas($this->parent, $oldTitle, $newTitle);
            }
        }

        return $this;
    }
public function setTitle($pValue, $updateFormulaCellReferences = true, $validate = true)
    {
        // Is this a 'rename' or not?
        if ($this->getTitle() == $pValue) {
            return $this;
        }

        // Old title
        $oldTitle = $this->getTitle();

        if ($validate) {
            // Syntax check
            self::checkSheetTitle($pValue);

            if ($this->parent) {
                // Is there already such sheet name?
                if ($this->parent->sheetNameExists($pValue)) {
                    // Use name, but append with lowest possible integer

                    if (Shared\StringHelper::countCharacters($pValue) > 29) {
                        $pValue = Shared\StringHelper::substring($pValue, 0, 29);
                    }
                    $i = 1;
                    while ($this->parent->sheetNameExists($pValue . ' ' . $i)) {
                        ++$i;
                        if ($i == 10) {
                            if (Shared\StringHelper::countCharacters($pValue) > 28) {
                                $pValue = Shared\StringHelper::substring($pValue, 0, 28);
                            }
                        } elseif ($i == 100) {
                            if (Shared\StringHelper::countCharacters($pValue) > 27) {
                                $pValue = Shared\StringHelper::substring($pValue, 0, 27);
                            }
                        }
                    }

                    $pValue .= " $i";
                }
            }
        }

        // Set title
        $this->title = $pValue;
        $this->dirty = true;

        if ($this->parent && $this->parent->getCalculationEngine()) {
            // New title
            $newTitle = $this->getTitle();
            $this->parent->getCalculationEngine()
                ->renameCalculationCacheForWorksheet($oldTitle, $newTitle);
            if ($updateFormulaCellReferences) {
                ReferenceHelper::getInstance()->updateNamedFormulas($this->parent, $oldTitle, $newTitle);
            }
        }

        return $this;
    }
Set title.

@param string $pValue String containing the dimension of this worksheet
@param bool $updateFormulaCellReferences Flag indicating whether cell references in formulae should
be updated to reflect the new sheet name.
This should be left as the default true, unless you are
certain that no formula cells on any worksheet contain
references to this worksheet
@param bool $validate False to skip validation of new title. WARNING: This should only be set
at parse time (by Readers), where titles can be assumed to be valid.

@return Worksheet