JavaScript string Object Replace method instance (for string substitution or regular substitution) _ Basics

JavaScript Replace method

The Replace method is used to replace some strings in strings, or to replace strings that match a regular match, and to return the replaced string. The syntax is as follows:

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Str_object.replace (REG_EXP/STR, replacement)

Parameter description:

Parameters	Description
Str_object	The string to manipulate (object)
Reg_exp/str	Necessary. The regular expression to match/the string to replace If Reg_exp has global flag G, then the Replace () method replaces all matching substrings. Otherwise, it replaces only the first matching substring.
Replacement	Necessary. The string to replace

String Substitution instance

The following example shows a string substitution instance of the Replace method:

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<script language= "JavaScript" >

var str = "Www.example.net";
document.write (Str.replace ("Example", "jb51"));

</script>

Run the example and output:

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Www.jb51.net

Note: string substitution replaces only the first qualifying string (only once), and if you want to replace all strings that match the required string, it is recommended to use a regular expression with global parameter g, as shown in the following example.

The regular expression string replaces an instance

The Replace method supports regular expression substitution in addition to simple string substitution:

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<script language= "JavaScript" >

var str = "Www.example.net is a example domains site of Inna.";
document.write (Str.replace (/example/, "jb51"));

</script>

Run the example and output:

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Www.jb51.net is a example domains site of Inna.

When you add a global flag G to a regular expression:

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<script language= "JavaScript" >

var str = "Www.example.net is a example domains site of Inna.";
document.write (Str.replace (/example/g, "jb51"));

</script>

Run the example and output:

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Www.jb51.net is a 5idev domains site of Inna.

Note that if you want to ignore case, you can add the I parameter:/example/gi.