Php character replacement method starting from the specified position

Definition and usage: the substr_replace () function replaces a part of the string with another string syntax: substr_replace (string, replacement, start, length) & lt ;? Phpechos

Definition and usage:

The substr_replace () function replaces one part of the string with another.

Syntax:Substr_replace (string, replacement, start, length)

2. Echo substr_replace ("hello world", "earth", 6 );
3. ?>

Parameter description

String is required, which specifies the string to be checked.

Replacement is required, specifying the string to be inserted.

Start:Required, specifying where to start replacement of the string.

Positive number-start replacement at the start offset

Negative number-replace with the start offset at the end of the string

0-START replacement at the first character in the string

Charlist:(Optional) number of characters to be replaced.

Positive number-length of the string to be replaced

Negative number-Number of replaced characters starting from the end of the string

0-insert instead of replace