Java 如何使用Optional.ofNullable()简化if语句
如何使用可选的.ofNullable()和lambda表达式等简化以下代码:Java 如何使用Optional.ofNullable()简化if语句,java,lambda,java-stream,Java,Lambda,Java Stream,如何使用可选的.ofNullable()和lambda表达式等简化以下代码: private String getStudentSection(Student student){ String section = "PRIMARY"; if(student != null){ int std = student.getStandard(); if(std > 5){ section = "
private String getStudentSection(Student student){
String section = "PRIMARY";
if(student != null){
int std = student.getStandard();
if(std > 5){
section = "SECONDARY";
}
}
return section;
}
我已尝试做以下工作:
使用
Optional.ofNullable(student)
然后映射并过滤表达式,但我无法确定如何返回该部分。您可以按如下方式执行:
String section = "PRIMARY";
Optional.ofNullable(student)
.map( i -> (i.getStandard() > 5) ? "SECONDARY" : section )
.orElse(section);