How To Loop All The Elements That Match The Regex?

Here is the case: I want to find the elements which match the regex... targetText = 'SomeT1extSomeT2extSomeT3extSomeT4extSomeT5extSomeT6ext' and I use the regex in javascript lik

Solution 1:

var reg = /e(.*?)e/g;
var result;
while((result = reg.exec(targetText)) !== null) {
    doSomethingWith(result);
}

Solution 2:

Three approaches depending on what you want to do with it:

• Loop through each match: .match

  targetText.match(/e(.*?)e/g).forEach((element) => {
     // Do something with each element
  });
  

• Loop through and replace each match on the fly: .replace

  const newTargetText = targetText.replace(/e(.*?)e/g, (match, $1) => {
    // Return the replacement leveraging the parameters.
  });
  

• Loop through and do something on the fly: .exec

  const regex = /e(.*?)e/g;  // Must be declared outside the while expression, 
                             // and must include the global "g" flag.
  
  let result;
  while(result = regex.exec(targetText)) {
    // Do something with result[0].
  } 
  

Solution 3:

Try using match() on the string instead of exec(), though you could loop with exec as well. Match should give you the all the matches at one go. I think you can omit the global specifier as well.

reg = new RegExp(/e(.*?)e/);   
var matches = targetText.match(reg);

Solution 4:

targetText = "SomeT1extSomeT2extSomeT3extSomeT4extSomeT5extSomeT6ext"    
reg = new RegExp(/e(.*?)e/g);   
var result;
while (result = reg.exec(targetText))
{
    ...
}

Solution 5:

I kept getting infinite loops while following the advice above, for example:

var reg = /e(.*?)e/g;
var result;
while((result = reg.exec(targetText)) !== null) {
    doSomethingWith(result);
}

The object that was assigned to result each time was:

["", "", index: 50, input: "target text", groups: undefined]

So in my case I edited the above code to:

const reg = /e(.*?)e/g;
let result = reg.exec(targetText);
while(result[0] !== "") {
    doSomethingWith(result);
    result = reg.exec(targetText);
}