使用不带正则表达式的循环匹配字符串上的模式

Question

i want to match pattern on the string using for loop and i create code like this :

function partialCheck(str, partial) {
  
  var pattern = [];
  for (var i =0; i <= str.length; i++){
    if(partial === str[i]+str[i+1]+str[i+2]){
      pattern.push(partial);
    }
  }
  return pattern;
}

on the test case, it should show the result like this :

console.log(partialCheck('abcdcabdabc', 'abc')); // ["abc","abc"]

console.log(partialCheck('accHghebchg', 'chg')); // ["cHg","chg"]

but on second case, it resulted like this :

console.log(partialCheck('accHghebchg', 'chg')); // ["chg"]

the question is it possible to put cHg to the array by ignoring case sensivity without using regex?

thanks before.

Answer 1

Convert to lowercase before comparing.

You can also use substr() instead of concatenating specific indexes of the string. This allows you to work with any size partial .

And you should push the substring onto the result array, not partial , so that you get the case from the string.

 function partialCheck(str, partial) { var pattern = []; partial = partial.toLowerCase(); for (var i = 0; i <= str.length - partial.length; i++) { if (partial === str.substr(i, partial.length).toLowerCase()) { pattern.push(str.substr(i, partial.length)); } } return pattern; } console.log(partialCheck('accHghebchg', 'chg'));

Answer 2

Yes and you can use substring to make the code simpler:

function partialCheck(str, partial) {

  var pattern = [];
  partial = partial.toLowerCase();
  for (var i =0; i <= str.length; i++){
    var substr = str.substring(i, i + 3);
    if(partial === substr.toLowerCase()){
      pattern.push(substr);
    }
  }
  return pattern;
}