What is the difference between wildcard characters * and ?

The wildcards * and ? have some differences in usage and matching range. Specific differences: 1. In terms of matching range, the wildcard * can match any length of character sequence, including letters, numbers, punctuation marks, spaces, etc., while the wildcard ? can only match one character; 2. In terms of usage, the wildcard * is used Fuzzy matching can match multiple characters or character sequences. The wildcard character ? is used for exact matching and can only match one character.

#The operating environment of this article: Windows 10 system, Dell G3 computer.

The wildcard characters * and ? are special characters commonly used in computer programming and are used to match part of a string or the entire string. They have some differences in usage methods and matching scope.

Wildcard characters represent zero or more characters. It can match strings of any length, including the empty string. For example, if we use wildcards and the pattern "ab*" to match the string "abcde", it will match "abcde" because * can match any length of characters.

Wildcard? represents a character. It can match any single character, but cannot match the empty string. For example, if we use the wildcard character ? and the pattern "a?c" to match the string "abc", it will match "abc" because ? can match any single character.

The wildcard * can match any sequence of characters, including letters, numbers, punctuation marks, spaces, etc. The wildcard character ? can only match one character, it cannot match special characters or spaces.

In terms of usage, wildcards are usually used for fuzzy matching and can match multiple characters or character sequences. For example, we can use the pattern "ac" to match the strings "abc", "abbc", "ac", etc. The wildcard character ? is usually used for exact matching and can only match one character. For example, we can use the pattern "a?c" to match the strings "abc", "adc", etc., but not "ac" or "abcc".

It should be noted that the wildcard characters * and ? may have different syntax and usage in different programming languages ​​and tools. In some regular expressions, * and ? may have different meanings or usages, so when used, they need to be adjusted and used appropriately according to the specific programming language or tool.

Summary

The difference between wildcard characters * and ? lies in the matching scope and usage method. * can match any length of character sequence, ? can only match one character; * is used for fuzzy matching, and ? is used for exact matching. According to specific needs and usage scenarios, we can choose appropriate wildcards to achieve string matching.

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