LWC variable not defined

I am creating a LWC data table and I would like that when the user click on "Edit Table" The fields in the table will get the inline edit true

import { LightningElement, wire, api } from 'lwc';
import LWCtable from '@salesforce/apex/PicklistHelper.LWCtable';
import { updateRecord } from 'lightning/uiRecordApi';
import { ShowToastEvent } from 'lightning/platformShowToastEvent';
import { refreshApex } from '@salesforce/apex';

// datatable columns



export default class InlineEditingTable extends LightningElement {
    recordData;
    saveDraftValues = [];
    @api selectedMarket;
    editValue = true;
    columns = [
        {
            label: 'Name',
            fieldName: 'Name',
            type: 'text',
        }, {
            label: 'Lead Source',
            fieldName: 'LeadSource',
            type: 'text',
            editable: editValue,
        }, {
            label: 'Number of Keys',
            fieldName: 'Number_of_Keys__c',
            type: 'Number',
            editable: editValue,
        }, {
            label: 'Status',
            fieldName: 'Status',
            type: 'Picklist',
            editable: editValue,
        }
    ];
    


    @wire(LWCtable, {MarketId: '$selectedMarket'})
    retrieveOutreachData({error, data}){
        if(data){
            this.recordData = data
            console.log('data', data)
            }
        }
       


    handleSave(event) {
        this.saveDraftValues = event.detail.draftValues;
        const recordInputs = this.saveDraftValues.slice().map(draft => {
            const fields = Object.assign({}, draft);
            return { fields };
        });

    

        // Updateing the records using the UiRecordAPi
        const promises = recordInputs.map(recordInput => updateRecord(recordInput));
        Promise.all(promises).then(res => {
            this.dispatchEvent(
                new ShowToastEvent({
                    title: 'Success',
                    message: 'Records Updated Successfully!!',
                    variant: 'success'
                })
            );
            this.saveDraftValues = [];
            return this.refresh();
        }).catch(error => {
            this.dispatchEvent(
                new ShowToastEvent({
                    title: 'Error',
                    message: 'An Error Occured!!',
                    variant: 'error'
                })
            );
        }).finally(() => {
            this.saveDraftValues = [];
        });
    }

    // This function is used to refresh the table once data updated
    async refresh() {
        await refreshApex(this.recordData);
    }
}

Here is my code; however everytime I launch the component I get that my editValue variable is not defined I am not sure what to do to make it work ..

thx you very much