Php case-insensitive conversion summary

1. convert string to lower-case strtolower (): This function converts all characters of the input string parameter to lower-case, and puts it back in a small form. convert character to uppercase strtoupper (): This function is opposite to the strtolower function. it converts all characters of the input character parameter to uppercase and returns the string in uppercase. use the same as str

1. convert string to lowercase

Strtolower (): This function converts all characters of the input string parameter to lowercase, and places the string back in a small form.

2. convert characters into uppercase letters

Strtoupper (): This function is opposite to the strtolower function. it converts all characters of the passed character parameter to uppercase and returns the string in uppercase. the usage is the same as that of strtolowe.

3. convert the first character of the string to uppercase.

Ucfirst (): This function is used to change the first character of a string to uppercase. This function returns the first character in uppercase. the usage is the same as that of strtolowe.

4. convert the first character of each word in the string to uppercase.

Ucwords (): This function converts the first character of each word in the input string to uppercase. for example, "hello world". after this function is processed, "Hello Word" is returned ". the usage is the same as that of strtolowe.