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1. Stringobject.charat ()
Function: Returns the subscript of a string
var str= "This is a string of strings"; Console.log (Str.charat (0))//This
2. Stringobject.charcodeat ()
Function: Method to return the Unicode encoding of the character at the specified position
var str= "This is a string of strings"; Console.log (str.charcodeat (0)) //This =>36825
3.string.fromcharcode ()
Function: Returns the corresponding character by Unicode encoding
Console.log (String.fromCharCode (36825,26159))//This is
Example: Finding a string is not a number
<body>
<input type= "text"/>
<input type= "button" value= "Detection"/>
<script>
var ainp = document.getelementsbytagname (' input ');
Ainp[1].onclick = function () {
var val = ainp[0].value;
if (Detectnum (val)) {
alert (' Congratulations, ' + val + ' all numbers ');
} else {
alert (' input error ');}
;
function Detectnum (str) {
var n = 0;
for (var i=0; i<str.length; i++) {
n = str.charcodeat (i);
if (n<48 | | n>57) return false;
}
return true;
}
</script>
</body>
4. Stringobject.indexof ()
Function: Method returns the position of a specified string value for the first time in a string.
Parameters: Str.indexof (lookup value, start lookup subscript), if the string value to retrieve does not appear, the method returns-1.
Example: Returns the subscript to find the corresponding character
<script>
var str = ' Xsxsxscdecdcdxsxsxs ';
var num = 0;
var s = ' xs ';
var arr = [];
for (; Str.indexof (S, num)!=-1;) {
num = str.indexof (s, num) + s.length
arr.push (num)
}
console.log (arr)
</script>
5. Stringobject.lastindexof ()
Function: To find the first occurrence of a specified string value in a string
6. Stringobject.substring ()
Action: Method is used to extract characters from the string mediation between the two specified subscripts.
7. Stringobject.touppercase ()
Function: Letters to uppercase
8. Stringobject.tolowercase ()
Function: Convert Letters to lowercase
9.stringobject.split ()
Function: Method for dividing a string into an array of strings
Parameters: (interception by what character, preserving array to ordinal)
Three ways to use
var str= "121314";
Str.split ("")//[1,2,1,3,1,4];
Str.split ("1")//[, 2,3,4];
Str.split ("", 2)//[1,2]
10.arrobject.join ()
Function: Method is used to put all elements in an array into a string. element is delimited by the specified delimiter.
Two ways to use
var arr = [1,2,3];
Arr.join ("")//123
arr.join ("-")//1-2-3
Example: highlighting the search keyword
<input type= "text" id= "oin"/>
<button> button </button>
var oin = document.getElementById ("Oin" );
var obtn = document.getelementsbytagname (' button ') [0];
var str = "The length of the arguments object is determined by the number of arguments, not the number of parameters."
A formal parameter is a variable that arguments the memory space inside a function, but it
does not overlap with the memory space of the object. For both arguments and values, the values are synchronized, but for one of
them that has no value, the value of the condition is not synchronized. The
following code can be validated. ";
var h = "";
Obtn.onclick = function () {
if (Oin.value = = "") {
alert ("Input is Empty");
return False
}
var s = oin.value;
if (Str.indexof (s) = = 1) {
alert ("No such number");
return False
}
var m = ' <span style= ' background-color:red ' > ' + S + ' </span> ';
str = Str.split (s);
h = Str.join (m)
document.body.innerhtml=h
}
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