JavaScript label mainly use with break and/or continue statement. label is unique name as an identifier for a statement.
In JavaScript, ECMA hasn't specified goto statement like in other programming languages, so you have to use labels along with break or continue statement.
General Syntax
label:label: {
// Scope of the block
}
Arguments
- label: Required, unique name as an identifier for referring to label that are specified with break or continue statement.
- { .. }: Optional, Identify the block of statement that are in labelled block.
Example (label with break statement)
<script>
outer: {
document.writeln("Inside outer start");
inner: {
for(var i = 1; ;) {
while(i <= 5){
document.writeln("i : " + i); // execute until i = 3
if (i == 3){
document.writeln("Skipped inner");
break inner; // skip inner block
}
i++;
}
}
}
document.writeln("Inside outer end");
}
</script>
Example Result
Example (label with continue statement)
<script>
for(var i = 1; i < 5; i++){
inner:
for (var j = 0; j < 5; j++){
if (j == 2){
document.writeln("skipped");
continue inner;
}
document.writeln("i : " + i + ", j :" + j);
}
document.writeln();
}
</script>
Example Result
Example (label with break statement and continue statement)
<script>
outer:
for(var i = 1; i <= 3; i++){
inner:
for (var j = 0; j <= 5; j++){
if (j == 2){
document.writeln("skipped");
continue inner;
} else if(j == 4){
document.writeln("terminated");
break inner;
}
document.writeln("i : " + i + ", j :" + j);
}
document.writeln();
}
</script>
Example Result
