Apex - do-while 循环

与在循环顶部测试循环条件的 for 和 while 循环不同，do...while 循环在循环底部检查其条件。< /p>

do...while 循环与 while 循环类似，不同之处在于 do...while 循环保证至少执行一次。

语法

do { code_to_execute } while (Boolean_condition);

流程图

示例

我们将更新列表中唯一的前 1 条记录，仅此而已。

// Code for do while loop
List<apex_invoice__c> InvoiceList = [SELECT Id, APEX_Description__c,
   APEX_Status__c FROM APEX_Invoice__c LIMIT 20];  //it will fetch only 20 records

Integer i = 0;
do {
   InvoiceList[i].APEX_Description__c = 'This is the '+i+' Invoice';
   
   // This will print the updated description in debug log
   System.debug('****Updated Description'+InvoiceList[i].APEX_Description__c);
   i++; // Increment the counter
} while (i< 1);   // iterate till 1st record only

apex_loops.html