Javascript：在一个字符串中，替换大写字母和它后面的所有字母

Question

I have a bunch of strings, dateTable, lastName, redColor and I want to remove the capitalized letter and all letters after that, for example, remove Table, Name, and Color and leaving only date, last, and red. Any help is appreciated!

Answer 1

Iterate through the letters and match them to a regex. Then use the sub string to get the string from start to index of the first upper case letter.

 var inputString = "What have YOU tried?";
var positions = [];
for(var i=0; i<inputString.length; i++){
if(inputString[i].match(/[A-Z]/) != null){
    positions.push(i);
break;

}
}
alert(positions);


var res = str.substring(1, postions[0]);

res should be the intended string

Answer 2

可以使用.replace()轻松完成：

"dateTable".replace(/[A-Z].*/, "")

Answer 3

Here is a method that will alert what you wanted - you can continue from there Check it:

function checkWord(word) {
  var foundFirst = false;
  var lengthToChop = 0;
  for (var i in word) {
     foundFirst = /^[A-Z]/.test( word[i])
     if (foundFirst){
        lengthToChop = i;
      break;
     }
  }
  alert(word.substring(0, lengthToChop));
}

Answer 4

Simple fast non-regex loop that breaks at the first capital letter.

function strip(str) {
  var i = -1, out = [], len = str.length;
  while (++i < len) {
    if (str.charCodeAt(i) >= 65 && str.charCodeAt(i) <= 90) break;
    out.push(str[i]);
  }
  return out.join('');
}

DEMO

Answer 5

try this code. No regular expressions... it should work and is pretty simple. Here is the fiddle... https://fiddle.jshell.net/4ku3srjw/2/

Just replace the string for the variable word and you'll see it works for what you want

var word = "lastName";

for (var i = 0; i < word.length; i++) {
  if (word[i] === word[i].toUpperCase()) {
    var choppedWord = word.substr(0, i)
  }   
}
alert(choppedWord);

Hope it helps