Found a total of 10000 related content
How to see if redis is started
Article Introduction：To determine whether Redis is started, you can: 1. Check whether the process exists; 2. Use redis-cli to connect to the Redis server.
2025-04-10
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671
How to determine whether the pointer is valid in C language
Article Introduction：NULL is essentially a null pointer to an empty address and does not mean invalid. Relying solely on ptr == NULL to determine that the pointer is valid is not enough to capture uninitialized, released or out of boundary memory. More reliable validity checking strategies include: checking the return value after allocating memory, setting the pointer to NULL after freeing memory, checking NULL for function parameters, using assertions and developing good programming habits (initializing pointers, checking validity, setting it to NULL after freeing, be careful of pointer operation).
2025-04-03
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479
How to check if a python string is empty or just contains spaces?
Article Introduction：There are three main ways to determine whether a Python string is empty or contains only spaces. 1. Use str.strip(): If the string is empty after the blank at both ends is removed, the original string is empty or full space; 2. Use str.isspace(): You must first confirm that the string is not empty, and then determine whether it only contains whitespace characters; 3. Combine nots and s.isspace() to uniformly determine whether the string is "invalid", that is, it is empty or contains only spaces. These methods are suitable for data cleaning, input verification and other scenarios. When selecting, it should be decided based on whether you need to distinguish between empty strings and full-space strings.
2025-06-26
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651
solana obtains wallet token balance and optimizes it
Article Introduction：In the past few days, I have been practicing using golang to call Solana contracts and switching languages. It feels not so easy. When doing evm, some ethereum codes are implemented in go. I feel that golang is like the first language of evm.
In the morning, I read questions from group friends
need
1. Want to determine whether Solana’s address is legitimate
2. Want to determine whether the legal address holds any one of the three tokens, that is, balance > 1
I just happened to be doing some exercises, so I simply wrote them down. The ideas are as follows:
Use the wallet address and token address to calculate the token's account address, and then call GetTokenAccountBalance
lokey :=so
2024-12-26
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1162
What is the difference between isset() and empty() in PHP?
Article Introduction：In PHP, isset() and empty() are used to check variable states, but have different uses. 1. isset() checks whether the variable is set and not null, and returns true even if the value is an empty string, 0 or false; 2. empty() checks whether the variable is empty, including empty string, 0, "0", null, false, empty array, etc., which are all considered "empty" and return true; 3. Use isset() to determine whether the variable exists, and use empty() to determine whether the variable has valid data; 4. For example, check whether the form field isset() to check whether the field is not empty; 5. Special cases such as "
2025-06-13
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733
Should `isdigit()` Take a `char` or `int` Input?
Article Introduction：Is isdigit() Function Intended for Char or Int Input?In the provided code snippet, the if condition employs isdigit() to determine whether the...
2024-10-31
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605
