NULLCHECK

例句：

1. 1. Null check is a critical step in the development process to ensure that all variables are initialized properly.
   null check是开发过程中的一个关键步骤，确保所有变量都已正确初始化。
2. 2. During testing, we often use null checks to catch potential bugs before they occur.
   在测试过程中，我们经常使用null检查来在问题发生之前捕捉潜在的错误。
3. 3. The null check function checks if a variable has been assigned a value before using it.
   null check函数在使用变量之前检查是否已分配了值。