Kennedybr var date p document writespeaker document writedate

Kennedybr var date p document writespeaker document

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"<p>John F. Kennedy</br>" ; var date = 'June 26, 1963</p>' ; document .write(speaker); document .write(date);
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Working with Strings (cont’ d.) String operators Concatenation operator (+): combines two strings var destination = "Honolulu" ; var location = "Hawaii" ; destination = destination + " is in " + location; Compound assignment operator (+=): combines two strings var destination = "Honolulu" ; destination += " is in Hawaii" ; Plus sign Concatenation operator and addition operator JavaScript, Sixth Edition 31
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Working with Strings (cont’ d.) Escape characters and sequences Escape character Tells the compiler or interpreter that the character that follows has a special purpose In JavaScript, escape character is backslash (\) Escape sequence Escape character combined with other characters Most escape sequences carry out special functions JavaScript, Sixth Edition 32
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JavaScript, Sixth Edition 33 Table 2-4 JavaScript escape sequences Working with Strings (cont’d.)
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Using Operators to Build Expressions JavaScript, Sixth Edition 34 Table 2-5 JavaScript operator types (continues)
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JavaScript, Sixth Edition 35 Table 2-5 JavaScript operator types (cont'd.) Using Operators to Build Expressions (cont’d.)
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Using Operators to Build Expressions (cont’ d.) Binary operator Requires an operand before and after the operator Unary operator Requires a single operand either before or after the operator JavaScript, Sixth Edition 36
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Arithmetic Operators Perform mathematical calculations Addition, subtraction, multiplication, division Returns the modulus of a calculation Arithmetic binary operators JavaScript, Sixth Edition 37 Table 2-6 Arithmetic binary operators
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Arithmetic Operators (cont’ d.) Arithmetic binary operators (cont’d.) Value of operation on right side of the assignment operator assigned to variable on the left side Example: arithmeticValue = x + y ; Result assigned to the arithmeticValue variable Division operator (/) Standard mathematical division operation Modulus operator (%) Returns the remainder resulting from the division of two integers JavaScript, Sixth Edition 38
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JavaScript, Sixth Edition 39 Figure 2-13 Division and modulus expressions Arithmetic Operators (cont’d.) var divisionResult = 15 / 6 ; var modulusResult = 15 % 6 ; document .write( "<p>15 divided by 6 is " + divisionResult + ".</p>" ); // prints '2.5' document .write( "<p>The whole number 6 goes into 15 twice, with a remainder of " + modulusResult + ".</p>" );↵ // prints '3'
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Arithmetic Operators (cont’ d.) Arithmetic binary operators (cont’d.) Assignment statement Can include combination of variables and literal values on the right side Cannot include a literal value as the left operand JavaScript interpreter Attempts to convert the string values to numbers Does not convert strings to numbers when using the addition operator JavaScript, Sixth Edition 40
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Arithmetic Operators (cont’ d.) Prefix operator Placed before a variable Postfix operator Placed after a variable JavaScript, Sixth Edition 41 Table 2-7 Arithmetic unary operators
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Arithmetic Operators (cont’ d.) Arithmetic unary operators Performed on a single variable using unary operators
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