PHP error what is an error?

There are two kinds of mistakes ：

• There is an error message
• No error message

Common error causes

Running environment error

There are many such problems , such as ：

• Multiple development environments are installed at the same time （xampp/wamp/phpstudy..）
• Insufficient authority （ Run without administrator privileges ）
• Wrong configuration modification （httpd.conf php.ini etc. ）
• PHP Version of the problem （ Suggest php5.6+）
• The alternative PHP Code editor （dw/hbuilder）
• ..

Wrong operation

Such mistakes are relatively elementary , such as ：

• Direct double click PHP file function
• Wrong URL entered
• File suffix error
• …

Such mistakes , Most of them didn't watch the video carefully , Or skip class . If such problems occur frequently , And at a loss , Then don't learn programming .

Code error

Newcomers often meet   Grammar mistakes , Such problems are easy to solve ,PHP The error prompt of is very accurate , And the code editor also has a warning color .

Because of the common problems of carelessness ：

• Missing space 、 Line breaking semicolon
• quotes 、 Brackets are not paired
• Magic method lacks underline
• Letter case
• Misspelled words
• ....

Common problems caused by unskilled grammar ：

• Array related syntax
• Class and object related syntax
• session/cookie
• Database query and SQL Statement writing

Although the code is executed in sequence , But don't ignore some grammar ：

• if{} The statements in are conditionally executed
• for/while The code in is executed repeatedly
• foreach The number of cycles is related to the number of array keys
• function , Called to execute
• Class method , Such as through “ object ” To carry out .
• ....

Coding errors , The garbled problem caused by ：

• File encoding error
• HTML meta Label usage error
• SQL Before query , No, SET NAMES UTF8
• Database encoding error

All in all , Grammatical errors are an entry-level problem ,  An error is a warning ： It means that you don't have a solid grasp of the knowledge points here .

AD： Little buddy in the Laboratory , Can pass this stage relatively quickly .

Business error

If one day , Your program rarely makes grammatical errors , It's about business 、 Logical errors related to requirements , So congratulations , You have advanced .

Server error

• linux （ File name case / System permissions ）
• …

Is it because I'm stupid that I made mistakes ？

Mistakes will always be with you , Even if you are an international bull . Different stages , There will be different mistakes .

Eliminating mistakes depends on a solid foundation 、 Enough code 、 Rich development experience . therefore , You often make some “ Daniel ” It seems that the mistake of a weak chicken , It's not because you're stupid , But because of the different stages you are in .

How to eliminate errors ？

decompose

Put a demand 、 A piece of code , Break it down into several steps , Is the key to solving the problem ！

For example, registered users ：

• Custom forms
• input data
• Submit data
• Check the data
• According to the verification results , Save or prompt error

First, it is decomposed into such steps , Then analyze the step where the problem occurs .