I have a string like:

def definition():

I want to change every instance of "def" but not the "def" in word definition.

like this

console.log("def definition():".specialReplace("def", "abc"));

and result should be

abc definition():

not

abc abcinition():

CodePudding user response：

Use String#replace or String#replaceAll with a regular expression:

const specialReplace = (str) => str.replaceAll(/\bdef\b/g, 'abc')
console.log(specialReplace("def definition")) // abc definition
console.log(specialReplace("def definition def")) // abc definition abc

In the regular expression, \b is a boundary type assertion that matches any word boundary, such as between a letter and a space.

Note that the same sequence \b is also used inside character class regular expression positions ([\b]), to match the backspace character.