What is the difference between a white box test and a black box test

Zeng Yandao “ A black cat , White cat , As long as you can catch a mouse, you are a good cat ”. The same is true of our tests , Whether it's a black box test or a white box test , As long as it can be tested bug, You can find the problem , Ensuring software quality is a good test method .

For novice software testing Xiaobai , Black box test and white box test are definitely one of the necessary vocabulary . that , What kind of black are they talking about , What's white ？ What is the difference between the two ？ take it easy , Next, Zhuji Xiaobian will answer your questions and solve your doubts .

The biggest difference between ： Focus on different objects

The biggest difference between black box testing and white box testing is that they focus on different objects during testing .

Black box testing is mainly aimed at the functions that show the program to users , White box testing is mainly aimed at the code logic of the program . The former tests the final function , The latter tests the daemon .

Black box testing

Black box , In fact, the literal meaning is to regard the test object as a non open and transparent black box . Black box testing is simply when testing , Regardless of the logical results in the box and the program running , Just check whether the function of the program conforms to its function description according to the requirements specification of the program , Verify that the output is incorrect .

White box testing

It's the opposite of black box , This approach is to think of the test object as an open transparent box . When testing , Testers will take advantage of the internal logic structure of the program and related information , By checking program status at different points , Check whether each path in the procedure can work correctly according to the predetermined requirements .

for instance

If you still don't understand, it doesn't matter , Xiaobian will give you an example to understand . If small A And small B It's a couple of brothers . Small A Going to dinner , But little A You need to work from home , So small A Let small B Go and buy him a suit , It's best to buy it back in two hours .

If in black box mode , Small A（ Testers ） Will be small B Make a list of purchases （ So-called ： Requirements specifications ）, Then tell Xiao B, Now it is 9:45, As long as 11:45 Buy everything before , Just take it home .

If it is under the white box test , The following situations may occur . Small B After reaching the designated shopping mall , Small A Start remote command by phone ： First buy a suit , The shop that sells suits , You are going to the designated one . Are you in the south gate now ？ If you go to the South Gate , go in , Keep to the right , Go all the way to the inside …… what ？ Your north gate ？ If it's the North Gate , Once in , Turn left first , Go to the end , To sell drinks , Turn right , Go straight ahead …… Tell the boss to buy a classic black suit , No other colors , The medium price one . Okay , Now go buy a tie . Be sure to watch the color of the tie , Don't spend too much , I want to buy something to match this suit . And match it according to my temperament , Choose a diamond decor , If not, just pure black ……

summary

There are always people who like to compare ： Which is better, black box test or white box test ？ Actually , It's not hard to see from the example above , The advantages of the two are different . But no matter which test method is used , There's no doubt it's all about finding defects , Discover the risks , To ensure that the software has fewer defects , Better quality . Black box and white box , Always interweave in our testing work .