Replace special characters in a string with underscore (_) in JavaScript
JavaScript replace() method is used to replace all special characters from a string with _ (underscore) which is described below:
- replace() method: This method searches a string for a defined value, or a regular expression, and returns a new string with the replaced defined value.
Syntax:
string.replace(searchVal, newvalue)
Parameters:
- searchVal: It is required parameter. It specifies the value, or regular expression, that is going to replace by the new value.
- newvalue: It is required parameter. It specifies the value to replace the search value with.
Return value: It returns a new string where the defines value has been replaced by the new value.
Example 1: This example replaces all special characters with _ (underscore) using replace() method.
<!DOCTYPE HTML> < html > < head > < title > Replace special characters in a string with _ (underscore) </ title > </ head > < body style = "text-align:center;" > < h1 style = "color:green;" > GeeksForGeeks </ h1 > < p id = "GFG_UP" style = "font-size: 16px; font-weight: bold;" > </ p > < button onclick = "gfg_Run()" > Click here </ button > < p id = "GFG_DOWN" style = "color:green; font-size: 20px; font-weight: bold;" > </ p > < script > var el_up = document.getElementById("GFG_UP"); var el_down = document.getElementById("GFG_DOWN"); var str = "This, is# GeeksForGeeks!"; el_up.innerHTML = str; function gfg_Run() { el_down.innerHTML = str.replace(/[&\/\\#, +()$~%.'":*?<>{}]/g, '_'); } </ script > </ body > </ html > |
Output:
- Before clicking on the button:
- After clicking on the button:
Example 2: This example replace a unique special character with _ (underscore). This example goes to each character and checks if it is a special character that we are looking for, then it will replace the character. In this example the unique character is $(dollar sign).
<!DOCTYPE HTML> < html > < head > < title > Replace special characters with _ (underscore) </ title > </ head > < body style = "text-align:center;" > < h1 style = "color:green;" > GeeksForGeeks </ h1 > < p id = "GFG_UP" style = "font-size: 16px; font-weight: bold;" > </ p > < button onclick = "gfg_Run()" > Click here </ button > < p id = "GFG_DOWN" style = "color:green; font-size: 20px; font-weight: bold;" > </ p > < script > var el_up = document.getElementById("GFG_UP"); var el_down = document.getElementById("GFG_DOWN"); var str = "A$computer$science$portal$for$Geeks"; el_up.innerHTML = str; function gfg_Run() { var newStr = ""; for(var i=0; i< str.length ; i++) { if (str[i] == '$') { newStr += '_'; } else { newStr += str[i]; } } el_down.innerHTML = newStr ; } </script> </ body > </ html > |
Output:
- Before clicking on the button:
- After clicking on the button: