متدهای تابع string در جاوا اسکریپت

var txt = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
var sln = txt.length;

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<p id="demo"></p>

<script>

var txt = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";

document.getElementById("demo").innerHTML = txt.length;

</script>

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26

var str = "Please locate where 'locate' occurs!";
var pos = str.indexOf("locate");

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<p id="demo"></p>

<script>

var str = "Please locate where 'locate' occurs!";

var pos = str.indexOf("locate");

document.getElementById("demo").innerHTML = pos;

</script>

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7

var str = "Please locate where 'locate' occurs!";
var pos = str.lastIndexOf("locate");

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<p id="demo"></p>

<script>

var str = "Please locate where 'locate' occurs!";

var pos = str.lastIndexOf("locate");

document.getElementById("demo").innerHTML = pos;

</script>

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21

var str = "Please locate where 'locate' occurs!";
var pos = str.indexOf("locate",15);

==================================

<p id="demo"></p>

<script>

var str = "Please locate where 'locate' occurs!";

var pos = str.indexOf("locate",15);

document.getElementById("demo").innerHTML = pos;

</script>

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21

var str = "Please locate where 'locate' occurs!";
var pos = str.search("locate");

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<p id="demo"></p>

<script>

var str = "Please locate where 'locate' occurs!";

var pos = str.search("locate");

document.getElementById("demo").innerHTML = pos;

</script>

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7

• slice(start, end)
• substring(start, end)
• substr(start, length)

var str = "Apple, Banana, Kiwi";
var res = str.slice(7, 13);

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Banana

var str = "Apple, Banana, Kiwi";
var res = str.slice(-12, -6);

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Banana

var res = str.slice(7);

==================

<p id="demo"></p>

<script>

var str = "Apple, Banana, Kiwi";

var res = str.slice(7);

document.getElementById("demo").innerHTML = res;

</script>

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Banana, Kiwi

var res = str.slice(-12);

var str = "Apple, Banana, Kiwi";
var res = str.substring(7, 13);

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Banana

var str = "Apple, Banana, Kiwi";
var res = str.substr(7, 6);

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Banana

str = "Please visit Microsoft!";
var n = str.replace("Microsoft", "W3Schools");

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<p id="demo">Please visit Microsoft!</p>

<script>

function myFunction() {

    var str = document.getElementById("demo").innerHTML;

    var txt = str.replace("Microsoft","W3Schools");

    document.getElementById("demo").innerHTML = txt;

}

</script>

str = "Please visit Microsoft and Microsoft!";
var n = str.replace("Microsoft", "W3Schools");

str = "Please visit Microsoft and Microsoft!";
var n = str.replace(/Microsoft/g, "W3Schools");

str = "Please visit Microsoft!";
var n = str.replace("MICROSOFT", "W3Schools");

str = "Please visit Microsoft!";
var n = str.replace(/MICROSOFT/i, "W3Schools");

var text1 = "Hello World!"; // String
var text2 = text1.toUpperCase(); // text2 is text1 converted to upper

برای تبدیل رشته به حروف کوچک از toLowerCase() استفاده کنید:

var text1 = "Hello World!"; // String
var text2 = text1.toLowerCase(); // text2 is text1 converted to lower

var text1 = "Hello";
var text2 = "World";
var text3 = text1.concat(" ", text2);

var text = "Hello" + " " + "World!";
var text = "Hello".concat(" ", "World!");

• charAt(position)
• charCodeAt(position)

var str = "HELLO WORLD";
str.charAt(0); // returns H

var str = "HELLO WORLD";

str.charCodeAt(0); // returns 72

var str = "HELLO WORLD";

str[0]; // returns H

var txt = "a,b,c,d,e"; // String
txt.split(","); // Split on commas
txt.split(" "); // Split on spaces
txt.split("|"); // Split on pipe

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<p id="demo"></p>

<script>

function myFunction() {

    var str = "a,b,c,d,e,f";

    var arr = str.split(",");

    document.getElementById("demo").innerHTML = arr[0];

}

</script>

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a

var txt = "Hello"; // String
txt.split(""); // Split in characters